HAP1 and breast cancer: We also found that when overexpressed, HA-TRPM7 has the capacity to bind native CNNM proteins in other cell lines (Hela, opossum kidney proximal tubule (OK), RPTEC/TERT1, and HAP1) and that endogenous TRPM7 interacts with native CNNM4 in ZR-75-1 breast cancer cells (S3 Fig).