ST6GALNAC1 and cancer: Aberrant sialoglycan expression, resulting from dysregulated glycan synthesis, encompasses two primary forms: the emergence of sialic-acid modified truncated O-glycans revealing the tumor-associated carbohydrate antigen sTn [28], linked to sialyltransferase ST6GalNAc1 overexpression and COSMC gene alterations [29,30], and augmented sialic acid residues on cancer cell surfaces, attributed to modulated sialyltransferase and neuraminidase activities [31].