The results showed that silencing of SHMT2 can decrease the expression levels of G1/S transition related protein (cyclin E1 and cyclin D1), while upregulation of SHMT2 can increase the expression levels of cyclin E1 and cyclin D1, indicating that SHMT2 facilitates the G1-to-S phase transition in BLCA cells. This evidence concerns the gene CCND1 and bladder transitional cell carcinoma.