CCDC69 and neoplasm: This suggests that mast cells may promote monocyte differentiation toward immune-activating phenotypes in LMS, a pathway potentially disrupted by ATRX mutations via downregulation of CCDC69. Although macrophage polarization and its effects on the tumor microenvironment have been widely studied [68], it remains unclear whether macrophage functional orientation is pre-determined during early monocyte differentiation.