"Pluripotent" cells are stem cells which can differentiate into any cell type in the body except extra-embryonic tissue. induced pluripotent stem cells (iPSCs) are subclass of pluripotent stem cells resembling embryonic stem cells (ESCs) that have been derived from adult differentiated cells. iPSCs are created by altering the expression of transcriptional factors in adult cells until they become like embryonic stem cells. As of November 2020, a popular method is to use modified retroviruses to introduce specific genes into the genome of adult cells to induce them to an embryonic stem cell-like state.