a-b: Human keratinocytes cultured in suspension in the presence of phenformin (Phen) or DMSO control, combined with 5 μM CsA or VIVIT for 24 h were collected for qRT-PCR (a) and western-blot (b) analysis of the keratinocyte differentiation markers CK1, CK10 and loricrin as indicated. c-d: Human keratinocytes transfected with a siRNA for calcineurin B1 (siCnB1) or a scrambled siRNA as a control (siCtrl) were cultured in suspension in the absence or presence of 1 mM phenformin for 24 h, then were lysed for qRT-PCR (c) and western blot (d) analysis of the keratinocyte differentiation markers CK1, CK10 and loricrin as indicated. a, c: **P<0.01; ***P<0.005. by Student’s two tailed t-test.