Should these approaches be pursued, it will be critical to assess the effects of these approaches in immune competent model systems as although Axl agonism may promote NK cell development and enhanced function [257] which could be beneficial for anti-tumor immune responses, Gas6-Axl activity has also been shown to promote the suppressive functions of Tregs in mice [303] which as discussed could enhance tumor growth in the bone. Here, GAS6 is linked to neoplasm.