A family of transcription factors characterized by the presence of highly conserved calcineurin- and dna-binding domains. NFAT proteins are activated in the cytoplasm by the calcium-dependent phosphatase calcineurin. They transduce calcium signals to the nucleus where they can interact with transcription factor ap-1 or nf-kappa b and initiate GENETIC TRANSCRIPTION of genes involved in cell differentiation and development. NFAT proteins stimulate T-CELL activation through the induction of IMMEDIATE-EARLY genes such as interleukin-2.