Induced pluripotent stem cells are made by reprogramming what type of cells?

Induced pluripotent stem cells (iPSCs) are generated by reprogramming adult somatic cells, allowing them to revert to a pluripotent state. This process enables these cells to differentiate into various cell types, similar to embryonic stem cells. The reprogramming typically involves the introduction of specific transcription factors that effectively reset the adult cells' developmental markers and capabilities.

While embryonic stem cells are already pluripotent and can differentiate into any cell type, they are not the starting point for creating iPSCs. Neural cells and epithelial cells are specific types of somatic cells but do not encompass the broader category of adult stem cells from which iPSCs are commonly derived. Hence, adult stem cells represent the correct answer as it encompasses various differentiated cells capable of being reprogrammed into iPSCs.