PGR and breast cancer: In comparison, luminal subtype breast cancers (expressing estrogen receptor and/or progesterone receptor) show a median infiltration of sTILs of between 7 and 10% [22,23,28] and of iTILs of between 1.5 and 5% [22,23,29], with a heterogenous prevalence of LPBC ranging from 2.9 to 12% [20].