KRAS and cancer: In addition to being a critical mediator in the suppression of RHOB promoter transcriptional activity via EGFR and ErB2 transfection, K-Ras decreased the promoter transcriptional activity of RHOB in a dose-dependent manner in NIH3T3 cells and suppressed RHOB protein levels in various types of cancer cells from pancreatic, cervical, and lung tumors.