IGF1 and cancer: Aberrant IGF‐1 signaling has been detected in various human cancer types, and there is evidence implicating IGF‐1 receptor activity in cancer cell proliferation, migration, and invasion as well as in resistance to therapeutic agents (Pollak et al, 2004; Mourkioti & Rosenthal, 2005; Clayton et al, 2011; Vigneri et al, 2015; Spadaro et al, 2017).