RETNLB and neoplasm: To further determine whether the ablation of FBXW7 was responsible for the increase in M2-like TAMs in the tumor microenvironment, we subsequently detected mRNA expression of the immunosuppressive factors Arginase 1 (Arg1), resistin like alpha (Fizz1), and chitinase-like 3 (Ym1) as markers of M2-polarized macrophages in tumor tissues.