0:00:06.688,0:00:09.778
Imagine two people are listening to music.

0:00:09.778,0:00:10.615
What are the odds

0:00:10.615,0:00:11.375
that they are listening

0:00:11.375,0:00:13.180
to the exact same playlist?

0:00:13.180,0:00:14.783
Probably pretty low.

0:00:14.783,0:00:18.370
After all, everyone has very different tastes in music.

0:00:18.370,0:00:19.735
Now, what are the odds

0:00:19.735,0:00:20.921
that your body will need

0:00:20.921,0:00:23.154
the exact same medical care and treatment

0:00:23.154,0:00:24.924
as another person's body?

0:00:24.924,0:00:26.301
Even lower.

0:00:26.301,0:00:27.772
As we go through our lives,

0:00:27.772,0:00:29.763
each of us will have very different needs

0:00:29.763,0:00:31.806
for our own healthcare.

0:00:31.806,0:00:34.439
Scientists and doctors are constantly researching ways

0:00:34.439,0:00:37.005
to make medicine more personalized.

0:00:37.866,0:00:39.031
One way they are doing this

0:00:39.031,0:00:41.644
is by researching stem cells.

0:00:41.644,0:00:45.034
Stem cells are cells that are undifferentiated,

0:00:45.034,0:00:48.560
meaning they do not have a specific job or function.

0:00:48.560,0:00:50.644
While skin cells protect your body,

0:00:50.644,0:00:52.358
muscle cells contract,

0:00:52.358,0:00:54.485
and nerve cells send signals,

0:00:54.485,0:00:58.915
stem cells do not have any specific structures or functions.

0:00:58.915,0:01:00.908
Stem cells do have the potential

0:01:00.908,0:01:04.264
to become all other kinds of cells in your body.

0:01:04.264,0:01:05.842
Your body uses stem cells

0:01:05.842,0:01:08.759
to replace worn-out cells when they die.

0:01:08.759,0:01:11.209
For example, you completely replace

0:01:11.209,0:01:14.556
the lining of your intestines every four days.

0:01:14.556,0:01:16.808
Stem cells beneath the lining of your intestines

0:01:16.808,0:01:19.719
replace these cells as they wear out.

0:01:20.349,0:01:22.971
Scientists hope that stem cells could be used

0:01:22.971,0:01:26.512
to create a very special kind of personalized medicine

0:01:26.512,0:01:29.691
in which we could replace your own body parts with,

0:01:29.691,0:01:32.188
well, your own body parts.

0:01:32.188,0:01:34.628
Stem cell researchers are working hard

0:01:34.628,0:01:36.696
to find ways in which to use stem cells

0:01:36.696,0:01:38.196
to create new tissue

0:01:38.196,0:01:39.572
to replace the parts of organs

0:01:39.572,0:01:43.118
that are damaged by injury or disease.

0:01:43.118,0:01:45.962
Using stem cells to replace damaged bodily tissue

0:01:45.962,0:01:48.675
is called regenerative medicine.

0:01:48.675,0:01:51.907
For example, scientists currently use stem cells

0:01:51.907,0:01:53.799
to treat patients with blood diseases

0:01:53.799,0:01:55.911
such as leukemia.

0:01:55.911,0:01:57.799
Leukemia is a form of cancer

0:01:57.799,0:02:00.051
that affects your bone marrow.

0:02:00.051,0:02:03.109
Bone marrow is the spongy tissue inside your bones

0:02:03.109,0:02:05.383
where your blood cells are created.

0:02:05.383,0:02:08.903
In leukemia, some of the cells inside your bone marrow

0:02:08.903,0:02:12.652
grow uncontrollably, crowding out the healthy stem cells

0:02:12.652,0:02:14.865
that form your blood cells.

0:02:14.865,0:02:16.991
Some leukemia patients can receive

0:02:16.991,0:02:19.069
a stem cell transplant.

0:02:19.069,0:02:20.753
These new stem cells will create

0:02:20.753,0:02:24.041
the blood cells needed by the patient's body.

0:02:24.041,0:02:25.558
There are actually multiple kinds

0:02:25.558,0:02:27.288
of stem cells that scientists can use

0:02:27.288,0:02:29.623
for medical treatments and research.

0:02:29.623,0:02:32.913
Adult stem cells or tissue-specific stem cells

0:02:32.913,0:02:34.710
are found in small numbers

0:02:34.710,0:02:37.046
in most of your body's tissues.

0:02:37.046,0:02:39.180
Tissue-specific stem cells replace

0:02:39.180,0:02:41.180
the existing cells in your organs

0:02:41.180,0:02:43.433
as they wear out and die.

0:02:43.433,0:02:45.676
Embryonic stem cells are created

0:02:45.676,0:02:48.827
from leftover embryos that are willingly donated

0:02:48.827,0:02:51.444
by patients from fertility clinics.

0:02:51.444,0:02:53.867
Unlike tissue-specific stem cells,

0:02:53.867,0:02:57.145
embryonic stem cells are pluripotent.

0:02:57.145,0:02:58.524
This means that they can be grown

0:02:58.524,0:03:01.430
into any kind of tissue in the body.

0:03:02.168,0:03:03.782
A third kind of stem cells

0:03:03.782,0:03:07.240
is called induced pluripotent stem cells.

0:03:07.240,0:03:10.988
These are regular skin, fat, liver, or other cells

0:03:10.988,0:03:12.156
that scientists have changed

0:03:12.156,0:03:15.146
to behave like embryonic stem cells.

0:03:15.146,0:03:17.450
Like embryonic stem cells,

0:03:17.450,0:03:20.401
they, too, can become any kind of cell in the body.

0:03:20.401,0:03:22.409
While scientists and doctors hope to use

0:03:22.409,0:03:24.218
all of these kinds of stem cells

0:03:24.218,0:03:26.825
to create new tissue to heal your body,

0:03:26.825,0:03:28.597
they can also use stem cells

0:03:28.597,0:03:32.134
to help understand how the body works.

0:03:32.134,0:03:34.640
Scientists can watch stem cells develop

0:03:34.640,0:03:36.908
into tissue to understand the mechnanisms

0:03:36.908,0:03:39.941
that the body uses to create new tissue

0:03:39.941,0:03:42.656
in a controlled and regulated way.

0:03:42.656,0:03:44.996
Scientists hope that with more research,

0:03:44.996,0:03:47.329
they can not only develop specialized medicine

0:03:47.329,0:03:49.239
that is specific to your body

0:03:49.239,0:03:51.036
but also better understand

0:03:51.036,0:03:52.294
how your body functions,

0:03:52.294,0:03:53.788
both when it's healthy

0:03:53.788,0:03:55.404
and when it's not.