Each condition in the key is shown in descending order of the percentage wound closure at 18 hours, expressed as mean ± standard deviation. ** P < 0.01; ***P < 0.001. Ctrl, control; IGF1R, insulin-like growth factor-1 receptor; inh, inhibitor; IR, insulin receptor; NHEK, normal human epidermal keratinocyte; NT, untreated control; Scr, scrambled control; ShRNA, short hairpin RNA; si, small interfering RNA; Veh, phosphate buffered saline vehicle control.