STAT3 and Alzheimer disease: To validate the functional implication of STAT3 in the reprogramming defects observed in AD-HIES cells, we investigated whether overexpression of functional wild-type STAT3 could improve reprogramming efficiency of AD-HIES fibroblasts (Fig. 2) and whether knocking down STAT3 in normal skin fibroblasts could mimic the reprogramming defects (Fig. 3).