ERBB2 and breast cancer: ECM1 has been associated with malignant phenotypes, such as proliferation, migration, invasion, stemness, and therapeutic resistance, in ovarian cancers, HER2 + breast cancers, and triple-negative breast cancers (Lee et al. 2014; Lee, Nam, Oh, Lim, Kim, et al. 2015; Lee, Nam, Oh, Lim, Lee, et al. 2015; Steinhaeuser et al. 2020; Yin et al. 2021).