ATP6V1C1 and breast cancer: Our data in the mouse breast cancer cell line 4T1 suggests that Atp6v1c1 may facilitate breast cancer growth and metastasis through the mTORC1 pathway, which prompted us to further determine whether ATP6V1C1 has a similar effect on the proliferation of, and the amino acid-sensitive mTORC1 activation in, other human breast cancer cell lines.