TP53 and neoplasm: However, a significant proportion of CRCs, which include mainly microsatellite instability-high (MSI-H) CRCs, and a subset of microsatellite-stable (MSS) sporadic CRCs, display a particular immunohistochemical p53 expression pattern characterized by an accumulation of p53 protein restricted to a limited number of tumor cells, a profile that we previously termed ‘restricted p53 overexpression’ [7].