FGF2 and cancer: It is in agreement with the phenotypic heterogeneity of endothelial cells within various cancer types (Maishi et al., 2019; Goveia et al., 2020), coupled with the variety of cues emanating from the tumor microenvironment, as EndMT subtuning seems to be regulated by various drivers like TGF-β and basic fibroblast growth factor (bFGF) (Xiao and Dudley, 2017).