Moreover, shRNA-mediated depletion of H2AX caused olaparib resistance in the triple-negative breast cancer cell line MDA-MB-436, that carries the BRCA1 c.5277+1 G > A mutation and shows complete loss of BRCA1 protein product28 (Supplementary Fig. 2b, c). This evidence concerns the gene H2AX and triple-negative breast carcinoma.