TMSB15B and breast carcinoma: Interestingly, AK291479 overlaps with the transcript of thymosin beta-15B (TMSB15B), one of the two isoforms of human thymosin beta 15, TMSB15A and TMSB15B, which show approximately equivalent levels of expression in MCF-7 breast cancer cells (Banyard et al., 2009).