“…Percentages for each alteration were obtained by totaling the number of positive cases (by IHC or sequencing for ErbB2, EGFR, AR) divided by total cases found in the literature [3, 4, 6, 7, 15, 18, 22, 28, 33, 39, 40, 44, 49–53, 55, 57–64, 67, 86–91]. Percentages representing expression are best estimates, as positivity was defined heterogeneously among studies.…”