Patterns of p53 and p21 immunohistochemical expression in high-grade lymphomas. Case F12, p53-mutated case: p53 overexpression in the majority of neoplastic cells (A); coupled with absent p21 (B). Original magnification × 400. Case F8, p53-nonmutated case: p53 is present in 25% of lymphomatous cells (C); p21 expression in a similar percentage of cells (D). Original magnification × 200. DO7 (p53) and EA10 (p21) MoAb. Streptavidin-peroxidase method with DAB; light hematoxylin counterstain.