SMAD4 and pancreatic neoplasm: Although we detected genomic alterations in the resected specimens after NAT, the variant allelic frequencies of 68 out of 242 mutations (28.1%) in the four major pancreatic cancer genes (KRAS, TP53, SMAD4, and CDKN2A) were less than 5%, which was lower than the common cutoff value of NGS tumor genomic profiling.