BCL2L11 and pachyonychia congenita: Studies conducted by Tanaka et al. indicate that metformin activated the expression of death receptor 5 (DR5), a receptor for TRAIL, and Bim with a proapoptotic function in the downstream of the TRAIL-DR5 pathway in PC cells; the authors suggest that the increased expression of these proteins may lead to the sensitization of TRAIL-induced apoptosis in PC cells [43].