Fig. 4. Correlation of CD68⁺ and CD163⁺ macrophage infiltration with OS.

The number of peritumoural and intratumoural CD68⁺ and CD163⁺ macrophages was determined by immunohistochemistry in primary melanoma tumours. Patients were stratified based on the density of infiltrating macrophages, and survival probabilities were predicted using Cox proportional hazards model and visualised with a Kaplan–Meier curve. Tumours were stratified as having CD68⁺ macrophages (positive) or having no CD68⁺ cells present (negative) (a, b). The level of CD163⁺ infiltration was stratified as high or low (c, d).