We found that the most commonly mutated somatic genes in tumor tissue and ctDNA in patients with mPDAC included KRAS, TP53, CDKN2A, SMAD4, and ARID1A, with a median somatic mutation number of 5 and 3 in tumor and blood samples, respectively, which is agreed by previous studies [41, 43, 44]. Here, CDKN2A is linked to neoplasm.