RAF1 and neoplasm: Na et al., in a study with 61 osteosarcoma patients, reported that RAF-1, pMEK1/2, and pERK1/2 were upregulated in tumor tissue, while these proteins were not expressed in normal bone tissue [60]. Furthermore, expression of RAF-1, pMEK1/2, and pERK1/2 was associated with the formation of distant metastases and poor overall survival.