To determine predictive biomarkers for prognosis by analyzing the association between tumor mutational burden (TMB) and mutant genes in patients with oral squamous cell carcinoma (OSCC) and to validate PCLO as an OSCC predictive biomarker, OSCC genetic mutation data were downloaded from The Cancer Genome Atlas (TCGA) and the International Cancer Genome Consortium (ICGC) database. Here, PCLO is linked to oral cavity squamous cell carcinoma.