ESR1 and breast cancer: After correcting for multiple comparisons, these cases demonstrated significantly higher rates of estrogen receptor (ER) negativity, HER2 positivity, CD163+ M2 macrophages, CAIX expression, and (IHC-defined) HER2 and basal intrinsic breast cancer subtypes, relative to the expression of these biomarkers among the G-CSFlow cases that comprised 53.3% of the study population (Table 1).