Suppression of CYP24A1 in MDA‐MB‐231 tumors reduced tumor weight and expression of Ki67 (proliferation marker) and CD37 (microvessel marker) while enhancing apoptosis and necrosis. Data also report gene expression profiles in MCF‐7 and MDA‐MB‐231 cells upon CYP24A1 silencing in vitro. The gene discussed is MKI67; the disease is neoplasm.