sCD163 is a marker of macrophage activation [65] and it has been associated with a number of inflammatory diseases such as atherosclerosis [80,81], hemophagocytic lymphohistiocytosis [82,83,84] and diabetes mellitus [85,86] including diabetic polyneuropathy [87], diabetic ketoacidosis [88] and proliferative diabetic retinopathy [89,90]. Here, CD163 is linked to proliferative diabetic retinopathy.