PHB2 and colorectal carcinoma: In order to determine whether the effect of PHB2 on CRC cell proliferation is due to regulation of complex I activity, we used two complex I inhibitors, rotenone, and IACS-10759, to inhibit complex I activity in PHB2-overexpressing NCM460 and SW620 cells (Fig. 6B) and chose the concentrations of two inhibitors which inhibited elevated complex I activity to levels similar to the control cells as working concentrations for the subsequent experiments.