CA2 and osteopetrosis: Furthermore, the proteomic profile indicated that the Khib-modified proteins has a significant effect on osteoclast function, such as the P00918 (carbonic anhydrase 2, CA2) with four differently Khib-modified sites [1], and the cross-talk between the DEPs and differentially expressed Khib-modified proteins may plays an important role in the pathogenesis of osteopetrosis.