KCNN4 and breast cancer: In earlier studies, we observed that growth factor-dependent changes in [Ca2+]i homeostasis required KCa3.1 [10], and IR as well as Ca2+, in turn, may further activate KCa3.1 in MMTV-PyMT breast cancer leading to a sustained entry of Ca2+ along its electrochemical gradient through e.g., Orai/STIM channels [22,23].