COL2A1 and Osteochondroma: Since Col2a1 is also expressed in perichondrial precursors Akiyama et al., 2005; Ono et al., 2014, the accelerated osteoarthritis phenotype in Nfatc1Col2a1;Nfatc2-/- mice could be secondary to the osteochondroma phenotype in these animals, instead of a direct beneficial role of NFATc1 in articular cartilage.