Ectopic overexpression of regulatory associated protein with mammalian/mechanistic target of rapamycin (RAPTOR) promotes the proliferation and cell cycle progression in colorectal cancer (CRC) cells by activating mTOR complex 1 and upregulating URB1 and cyclinA2 (CCNA2) expression. A and B, The transfection efficiency of RAPTOR overexpression plasmids in CRC cells was measured by using quantitative real‐time PCR (qRT‐PCR) and western blot. RAPTOR represents the RAPTOR overexpression group, and Vector represents the control group. C, Cell viability was determined by a CCK‐8 assay after RKO and HCT116 cells were transfected with RAPTOR overexpression and negative control vector plasmids. Scale bars: 50 μm (×100 magnification). D, The images show that the cell cycle progression of CRC cells was acutely promoted by RAPTOR overexpression. E and F, By using qRT‐PCR and western blot analysis, overexpression of RAPTOR distinctly provoked mTORC1 signaling and increased URB1, and CCNA2 expression in RKO cells. Data are mean ± SD (n = 3), *P < .05, **P < .01 and ***P < .001