KRAS and neoplasm: The relationship among ctKRAS G12D mutation in the buffy coat, ctKRAS G12D mutation in ascites, miRNA-31-5, and KRAS immunohistochemistry (IHC) results in the tissues of origin were assessed to demonstrate that ctDNA isolated by a PDA–silica-coated alginate bead and by anti-CD63 immobilized alginate beads could reflect molecular characteristics of the primary tumor.