ERBB2 and breast carcinoma: In breast carcinomas of no special type, reduced PR immunostaining was linked to advanced tumor stage (p < 0.0001), lymph node metastasis (p < 0.0001), high tumor grade (p < 0.0001), distant metastasis (p < 0.0001), positive HER2 status (p < 0.0001), and shorter overall survival (negative vs. any positivity, HR 1.8, 95% CI 1.3-2.5, p = 0.0127; Supplementary Figure 2).