A stem cell transplant is often the best option to treat blood cancers, such as leukemia, lymphoma, multiple myeloma and myelodysplastic syndrome, as well as bone marrow failure syndromes like aplastic anemia.

To understand the different types of stem cell transplants and how they work, we spoke with Amin Alousi, M.D. Here’s what he had to say.

Stem cells are the “seeds” that...

Lymphocytes are a type of white blood cell. They help make up our immune system. Because they have cellular memory, any time they’re exposed to a virus, bacteria or other pathogen for a second time, they recognize the danger and start reproducing themselves to fight off an infection. This means they play a vital role in keeping us healthy.

But what’s considered a “normal” range of lymphocytes? Does it mean you have cancer if they...