Previous <i>in vitro</i> studies suggest that MUC21 may inhibit cancer cell adhesion, indicating its potential significance in OSCC pathogenesis.<h4>Methods</h4>We analyzed microarray data from 10 OSCC tissues and paired adjacent normal tissues (para-OSCC), along with GEO and TCGA RNA-seq datasets, to identify differentially expressed genes, including MUC21. This evidence concerns the gene MUC21 and cancer.