RB1 and cancer: Given that MDM2 is implicated in epithelial‐mesenchymal transition (EMT),12 in degradation of the transcription factor FOXO3a,13 the CDK inhibitor p21(Waf1/Cip1),14 and the tumor suppressor Rb,15 as well as in the stabilization of the transcription factor E2F1,16 our results suggest that MDM2 might determine the malignant phenotype of FOLRα‐expressing cancer as a result of the operation of a FOLRα‐PHB2‐MDM2 axis (Figure 4G).