Previously, our laboratory demonstrated that SFN could induce cell cycle G1/S delay in MDA-MB-231 breast cancer cells, and outcomes from qPCR analysis were further approved using microarray analysis, indicating substantial SERTAD1, CCDN2, and HDAC3 downregulation, as well as the noticeable repression of CDK4 after exposure to SFN. The gene discussed is CDK4; the disease is breast cancer.