Recent studies have suggested that decreased bone resorption could be caused by abnormalities in the RANKL/RANK/OPG system, lack of c-Fos protein, and mutations in M-CSF, while mutations in the vacuolar (H+)-ATPase (V-ATPase) subunit, loss of CLC-7 chloride channels, and a shortage of cathepsin K are the most common reasons for osteopetrosis caused by bone resorption disorders. This evidence concerns the gene CSF1 and osteopetrosis.