To confirm the association between HER2 addiction and glycolytic metabolism and to exclude a possible role of cells in the tumor microenvironment in regulating intratumor lactate content, we performed in vitro analyses using the following HER2‐positive tumor cell lines: ZR75.30, SKBR3, BT474, HCC1954, MDAMB361, and MDAMB453. This evidence concerns the gene ERBB2 and neoplasm.