It is demonstrated that protein arginine methyltransferase 6 (PRMT6), poly(ADP‐ribose) polymerase 1 (PARP1), and the cullin 4 B (CUL4B)‐Ring E3 ligase (CRL4B) complex interact to form a transcription‐repressive complex that co‐occupies the core clock gene PER3 promoter, promoting the proliferation and metastasis of breast cancer by interfering with circadian rhythm oscillation. Here, PARP1 is linked to breast carcinoma.