PGF and breast carcinoma: Importantly, PGF is highly upregulated in multiple cancers including breast cancer, colorectal cancer, and endometrial carcinoma, and its expression levels positively correlated with poor prognosis, including tumor reoccurrence and metastasis, of the patients (Parr et al., 2005; Wei et al., 2005; Coenegrachts et al., 2013).