Correlating morphology and CD68 expression (P = 0.010), according to Z-tests with Bonferroni correction, centroblastic tumours were associated with low expression of CD68 macrophages (76.7% vs. 43.5%); in comparison, high-grade tumours exhibited a greater association with high CD68 expression (13% vs. 0%). The gene discussed is CD68; the disease is neoplasm.