Among all prognostic genes (n = 557), about 30% were not assigned to any functional group by Reactome pathway enrichment analysis of luminal (33.9%: adverse, 29.1%; favorable, 4.8%, Fig. 4A, upper panel), HER2-enriched (36.7%: adverse, 25.0%; favorable, 11.7%, Supplementary Fig. 10B, upper panel), and triple-negative (31.4%: adverse, 21.0%; favorable, 10.4%, Fig. 4B, upper panel) breast cancers. This evidence concerns the gene ERBB2 and breast cancer.