SERPINB1 and breast cancer: Observational studies have indicated that high expression of KLK6, CLMN (encodes Calmin, a membrane calponin‐like protein), and EFTUD1 (encodes elongation factor like GTPase 1, a ribosome biogenesis factor) in breast tumors promotes better survival, supporting a link between vitamin D signaling and disease outcomes.(77) SERPINB1 encodes Serpin Family B Member 1 (a proteinase that primarily functions in an anti‐inflammatory capacity), but its role in breast cancer has not been well studied.