From each breast cancer subtype, we selected an NER deficient (D) and NER intact (I) cell line pair for functional analysis: basal/triple negative HCC1806 (D) and MDA-MB-231 (I), luminal MCF7 (D) and MDA-MB-361 (I), and HER2 SKBR3 (D) and MDA-MB-453 (I). The gene discussed is ERBB2; the disease is breast carcinoma.