IL10 and neoplasm: Monocytes differentiate into TAMs with capacity to secrete pro- and also anti-inflammatory mediators depending on their differentiation states .3 While initially M1 macrophages can inhibit tumor growth, later M2-like macrophages create a favorable pro-tumorigenic microenvironment and are a source of high levels of immunosuppressive cytokines such as IL-10 .2,24,25 Importantly, IL-10 plays a role in enhancing IgG4 production on site.