NFATC2(Nuclear factor of activated T-cells, cytoplasmic 2),also known as NFATP or the 'preexisting component' of NFAT, is present in the cytosolic fraction of unstimulated T cells, which is also a member of the nuclear factor of activated T cells (NFAT) family. The NFATC2 gene is mapped on 20q13.2. NFATC2 is highly homologous to NFATC1 over a limited domain which shows similarity to the Dorsal/Rel family but has a wider tissue distribution. Ectopic expression of NFATC2 inhibited the basal activity of the human CDK4 promoter. Additionally, both Calna-/- and Nfatc2 -/- mice had elevated protein levels of Cdk4, confirming a negative regulatory role for the calcineurin/NFAT pathway. NFATC2 controls myoblast fusion at a specific stage of myogenesis after the initial formation of a myotube and is necessary for further cell growth. Overexpression of NFATC2 promoted differentiation of osteoclast precursor cells into tartrate-resistant acid phosphatase-positive (TRAP-positive) multinucleated osteoclast-like cells even in the absence of RANKL