ECM1 and breast neoplasm: Because higher levels of phospho-ERK and phospho-EGFR, EGFR, and HER3 expression in BT-474 TR cells (Additional file 3: Figure S2C) and the level of ECM1 also correlated strongly with levels of phosphorylated ERK in breast tumor tissues (Additional file 3: Figure S2D), we hypothesized that ECM1 may be related to EGFR-dependent ERK activation, which can promote cell proliferation.