GAS6 and cancer: Some studies support the hypothesis that bone metastatic cancer cells disseminate in the same manner as HSCs homing in bone marrow, based on several factors that have been implicated in how tumor cells hijack the HSC niche, such as TANK-binding kinase 1-TBK1 (an enzyme with kinase activity, regulates cell proliferation, apoptosis, autophagy, and anti-tumor immunity) and Growth arrest-specific 6-GAS6 (involved in the stimulation of cell proliferation) [55].