Pamidronate reduced the expressions of the osteoclastogenesis-related proteins, RANKL and cathepsin K in RAW 264.7 cells, indicating it inhibited osteoclast differentiation, which is in-line with the reported disappearance of osteoclasts in bisphosphonate-treated animals (Kameka et al., 2014; Kawata et al., 2004; Mayahara & Sasaki, 2003) and has implications regarding the effects of pamidronate effects on osteolytic diseases such as including osteoporosis, fibrous dysplasia, Paget’s disease, and Gorham’s disease (Hammer et al., 2005; Kravets, 2018; Saraff et al., 2018), etc. This evidence concerns the gene CTSK and Gorham-Stout disease.