DPP4 and neoplasm: By overlapping with known oncogenes and tumour suppressors17 (Fig. 2D), we found five oncogenes (GALR2, IGF2, IGF1R, MAS1, and TAC1) and nine tumour suppressors (AGTR1, DKK1, DPP4, EDNRB, GALR1, IGF1, IGF2R, KISS1, and NGFR).