GABPA and melanoma: Although a previous report (Makowski et al. 2016) using a similar pull-down approach had reported GABPA binding in the presence of both the endogenous ETS sites and de novo ETS sites created by the −124C > T mutation using UACC903 (melanoma; −124C > T mutant) nuclear extracts (Fig. 1A; Supplemental Table S1), we could not detect GABPA enrichment to any of the nine probes using antibodies against endogenous GABPA (Supplemental Fig. S1A), consistent with our mass spectrometry results.