ESR1 and neoplasm: SRA1 is able to activate the estrogen receptor to increase proliferation and its expression could be indicative of tumor grade or type, as higher expression of SRA1 was observed in ER-α-positive/PR-negative tumors compared to ER-α-positive/PR-positive tumors (Leygue et al., 1999), but although SRA1 enhances mammary gland proliferation, it is insufficient for malignant transformation (Lanz et al., 2003).