Human cell-processed therapeutic products (hCTPs) are expected
to provide novel breakthrough therapies for currently lifethreatening
or incurable diseases. In the clinical applications of
hCTPs to patients, however, one of the major concerns is the
tumorigenic cellular impurities in the products. Since pluripotent
stem cells (PSCs), such as embryonic stem cells and induced
pluripotent stem cells, are tumorigenic [1e3], there is a risk of tumor
formation if the products contain the residual undifferentiated PSCs.