SCGB1A1 protein, a homologue of rabbit uteroglobin, is a phospholipase A2 inhibitor. SCGB1A1 is regulated by AP-1, octamer, and hepatocyte nuclear factor-3 (HNF-3) family transcription factors. SCGB1A1 expression changes in relation to the ovarian menstrual cycle, and expression in human endometrium may be stimulated by progesterone, suggesting that SCGB1A1 may regulate eicosanoid levels in the human uterus. SCGB1A1 is expressed in nonciliated airway epithelial cells in the lung and in urogenital secretions. SCGB1A1 is involved in modulating inflammation in airway passages and may play a role in asthma. Overexpression of SCGB1A1 in the non-small cell lung cancer cell line A549 was shown to result in the near absence of MMP-2 and MMP-9 matrix metalloproteinases and a reduction in invasiveness, indicating that loss of SCGB1A1 may contribute to carcinogenesis.