Even though TP53 has been recognized as the most common somatically mutated gene in ER- breast tumors [64], our expression-based TWASs of ER- breast cancer for the joint analysis of 11 tissues as well as breast tissue alone were the first TWAS to identify TP53. In addition, the PIP of 0.87 in breast and 0.87 in cultured fibroblasts for TP53 were relatively high, which are corroborated by numerous experimental studies showing that the expression of TP53 in these two tissues impacts breast cancer etiology [65, 66]. The gene discussed is TP53; the disease is breast cancer.