CYP27A1 and breast cancer: In consistence with the observation in ovarian cancer, Liqian Ma et al. reported that CYP27A1 was highly expressed in myeloid cells, and breast cancer metastasis was reduced after myeloid specific knockout of CYP27A1 in mice, suggesting that CYP27A1 axis in myeloid cells played an oncogenic role in breast cancer (Ma et al., 2020).