Research on stem cells began in the 1950s, when scientists discovered at least two kinds of stem cells inside bone marrow, according to the National Institutes of Health. Today, stem cell research continues to play a huge role in the fight to combat disease. While stem cells are always in the news, whether for controversy or scientific discovery, the nature of stem cells is not always clear. Here is a guide to help you understand stem cells and what they hold for the future.

What are stem cells?
All of your cells, including stem cells, are the basic structures that make up your body tissue. Stem cells are very much like the rest of your body’s cells, which are considered the building blocks of life. Nonetheless, stem cells differ in fundamental ways. Stem cells can be found in human embryos, adult organs and tissues, but regardless of where they are found, stem cells have singular properties that distinguish them from most cells. The vast majority of your body’s cells are specialized, which means they are designed to perform a specific function. For example, muscle cells take on the ideal shape and structure to allow for muscle function. Many such specialized cells, including muscle, blood and nerve cells, do not normally duplicate and reproduce. Stem cells, on the other hand, can divide and multiply for long periods. Stem cells are not yet specialized, and they have the ability to specialize in a process called differentiation. While generally all cells that have these functions are stem cells, scientists classify stem cells into different types, primarily as embryonic or adult stem cells.

Embryonic stem cells
Embryonic stem cells come from embryos that are between three and five days old that�� have been fertilized in vitro (outside the body) and donated for research. Human embryonic stem cells are derived from an embryo in the pre-implantation stage, then transferred to a laboratory culture dish, where a nutrient broth helps stem cells divide and multiply. As the cells develop, they prepare to differentiate, then specialize, to perform a specific function. During this process, they prepare to become cells for organs like the heart, brain and liver. Today, scientists can use “recipes” to direct the stem cells toward some forms of specialization.

Adult stem cells
Adult stem cells, also known as somatic stem��cells, can be found all over the human body within brain tissue, bone marrow, blood vessels, skin, teeth and so on. Within each tissue, these stem cells are believed to be limited to a special area called the stem cell niche. These stem cells generate new cells, which keep the organ tissue functioning properly. While embryonic stem cells can become any type of cell, researchers believe adult stem cells��may��only differentiate into��cell types��from their original tissue. In short, stem cells from the brain can only specialize and become one of the various types of brain cells. However, scientists have discovered a way to program the adult stem cells into acting more like embryonic stem cells, producing induced pluripotent stem cells (iPSCs). Already, iPSCs have been used for drug development and disease research, and they will hopefully play a role in organ transplants, according to the NIH.

Potential treatments
Stem cells can provide an invaluable resource for understanding and treating serious diseases. Embryonic stem cells shed some light on cell division and differentiation. Serious medical problems can arise when these two processes are disrupted. Cancer, for example, occurs when the body’s cells multiply too rapidly. Scientists hope to study embryonic stem cells and figure out how to prevent or stop this abnormal multiplication. Researchers also use stem cells to test the safety and effectiveness of new drugs, such as anti-tumor medications for cancer treatments. In addition, stem cells’ ability to specialize into new, healthy organ tissue may alleviate the pressing need for transplanted organs. In this way, stem cells are like new seeds that can turn into any plant you need. Replacement cells can treat debilitating and life-threatening diseases, such as Alzheimer’s, skin burns, spinal cord damage, stroke, heart disease, diabetes and various forms of arthritis.