HSPA4 and neoplasm: Primarily, HSPH (from the HSP70 superfamily), HSP90 (HSPC), and type I and type II chaperonins (from the CHAP family) were found expressed at higher levels in Luminal B, HER2 and Basal tumours than in Luminal A subtypes, while for the HSPB family, Basal tumours showed an overall less marked decrease of these group of genes with respect to normal tissue, which represents greater expression of them with respect to the rest of the subtypes, especially in relation to HER2 and Luminal B types (Additional file 10 A).