CDK4 and neoplasm: In addition, similar to YMG25R parent tumor (Fig. 3A-B), YMG25R xenograft cells highly expressed phospho-PDGFRA, -AKT, and -ERK as well as CDK4 and MDM2, and phospho-Rb, as compared to sham control (Fig. 4F, Additional file 1: Fig. S4C–D).