Nuclear factor of activated T cells (NFAT), which is the pharmacological target of immunosuppressants cyclosporine and tacrolimus, has been shown to play an important role in T cells (immune system) and many biological events. Accumulating studies have indicated that NFATs are involved in many aspects of cancer, including carcinogenesis, cancer cell proliferation, invasion, metastasis, angiogenesis, drug resistance and tumor microenvironment. As the key section of the adaptive immune response, the T cell receptor (TCR)-calcium-calcineurin signaling pathway could lead to T cell activation. The 'nuclear factor of activated T cells' proteins are transcription factors that promote expression of a panel of genes required for activation.