MSR1 and gastric cancer: IHC staining for the specific M2 marker CD204 in 142 gastric cancer specimens was performed, and the staining was scored as grade 0 (no cells with positive staining), grade 1 (less than 25% cells with positive staining), grade 2 (25–50% cells with positive staining), and grade 3 (more than 50% cells with positive staining).