SMAD4 and neoplasm: Expression of PD-L1 (clone 28 - 8) was also assessed in tumor specimens from 64 patients.<h4>Results</h4>The frequency of genetic alterations (GAs) in Chinese patients with AMPAC was found to be distinctive, with TP53, KRAS, SMAD4, APC, CTNNB1, ARID1A, and CDKN2A emerged as the most frequently mutated genes.