PGR and breast cancer: Notably, in breast cancer, PRMT1 promotes tumor cell proliferation, tumorigenesis, and metastasis by methylating substrates such as H4 [52], BRCA1 [53], C/EBPα [54], EZH2 [55–57], Progesterone Receptor (PR) [58], PHGDH [59], and SRSF1 [60].