ESR1 and invasive breast carcinoma: Besides the full-length transcript, six other splice variants have been identified for this gene: survivin-2a, -2b, -2b+, -3b, -ΔΕx3 and survivin-image (SI), each correlating with tumor grade and size, cancer type, lymph nodes and estrogen receptors in BrCa with variable effect on patient prognosis [98].