TGFB1 and systemic sclerosis: Moreover, MerTK was significantly higher expressed also at gene expression level in cultured MDMs obtained from SSc-ILD patients compared to cultured MDMs from HS together with the gene expression of TGFβ1, another functional marker of the profibrotic M2 phenotype (p < 0.05; p < 0.01, respectively) (Fig. 2B).