MAT2A and head and neck squamous cell carcinoma: MAT2A was upregulated in cholangiocarcinoma (CHOL), colon adenocarcinomas (COAD), glioblastoma (GBM), head and neck squamous cell carcinoma (HNSC) with human papillomavirus (HPV) infection, LIHC, pheochromocytoma and paraganglioma (PCPG), and stomach adenocarcinoma (STAD), which were marked in red (Figure 3).