SERPINA1 and Hand-foot syndrome: To identify an optimal protocol for generating iHeps from HFs (from human foreskin), we tested the previously reported combinations of TFs in parallel transdifferentiation experiments and analyzed the efficiency of iHep conversion by measuring the mRNA levels for liver markers [35–37] such as ALBUMIN, TRANSFERRIN, and SERPINA1 at different time points (Fig. 1B, Supplementary Fig. S1A).