ERBB2 and breast cancer: With respect to breast cancer cells, it was demonstrated that knockdown of H6PD decreased proliferation and migration of triple-negative (progesterone receptor (PR), estrogen receptor-α (ER), HER2 receptor (HER2)) SUM159 cells, in PR+/ER+/HER2− MCF7 cells, and in triple-negative MDA-MB-231 cells [11].