MAPK3 and cancer: IGRM57 exhibits PDGFRA gene amplification though no hot spot mutations have been found in PDGFR, RET, or KIT. PDGFRs, which have been implicated in cancer [47,52,53] may play a role in this tumor, which is supported by the efficient inhibition not only of PDGFRB but also of its signaling kinases AKT and ERK1/2.