GDF15 and cancer: Interestingly, recent studies have also linked RET to alterations in tumor metabolism, an emerging hallmark of cancer, through a novel ligand complex involving Growth Differentiation Factor 15 (GDF15) and the GDNF Family Receptor α-like (GFRAL) (Emmerson et al., 2017; Hsu et al., 2017; Mullican et al., 2017; Yang et al., 2017).