Retrospective biomarker analyses in patients with locally advanced HNSCC treated with primary RCT or PORT-C demonstrated that the expression level of SLC3A2/CD98hc is a promising biomarker of both locoregional tumor control (LRC) and distant metastases in patients with HPV-negative tumors, i.e., increased LRC rates correlate with low SLC3A2 mRNA and protein expression [2,9]. Here, SLC3A2 is linked to head and neck squamous cell carcinoma.