Cyclosporin A (CsA) treatment, a calcineurin inhibitor, reversed the nuclear accumulation of NFATc1 in BC cells, which was upregulated by RCAN1.4 knockout (Fig. 2k), indicating that RCAN1.4 regulated the nuclear localization of NFATc1 by inhibiting calcineurin activity. Here, NFATC1 is linked to breast cancer.