Gain‐ and loss‐of‐function studies showed that SMIM30 reduced cytosolic calcium level, increased the protein levels of key components in the Rb pathway, including CDK4, cyclin E2, E2F1 and pRb, and promoted the G1/S transition and cell growth; and calcium chelator attenuated the effect of SMIM30 silencing, suggesting that SMIM30 may promote tumor cell growth by regulating intracellular calcium concentration. This evidence concerns the gene RB1 and neoplasm.