ART4 and cancer: For example, circulating β-galactoside α2-6Sialyltransferase 1 can modify cell surface glycoproteins with α2-6Sia when CMP-sialic acid is released from either inflammation-activated platelets (56) or tumor-induced platelet aggregation, which has long been known to be involved in tumor progression in several types of cancers, including lung, colon, breast, pancreatic, ovarian, and brain (57, 58, 59, 60, 61) This implies that cancer cells not expressing α2-6Sia can be converted into α2-6Sia–expressing cells through this inflammation or cancer-induced, platelet-related mechanism.