IGF1 and neoplasm: Insulin-like growth factor (IGF) is one of the most studied pathways of ACC given that the 80–90% of patients have overexpression of IGF2 (Gicquel et al. 1994, Giordano et al. 2003, Almeida et al. 2008, Peixoto Lira et al. 2016, De Martino et al. 2019), one of the IGF ligands, which supports tumor growth (Guillaud-Bataille et al. 2014).