CD68 and neoplasm: However, there were differences in CD68 staining: the CD68-immunolabelled cells in the clear/responsive areas were restricted to the paucicellular/empty cores and had the round morphology we have previously found to be associated with M1-like macrophages infiltrating sunitinib-treated tumours [15] (Figure 5J, 5K), whereas CD68 mainly decorated the inside margins of the cell layer surrounding the necrotic areas, and there were no CD68+ cells in the central core (Figure 5L, 5M).