An analysis of TCGA HNSCC data showed that CD274 expression was negatively correlated with the level of ferroptosis inhibition genes (GPX4, GSS, GCLC, SLCA11, SLC3A2) and positively correlated with the ferroptosis promotion gene ACSL4 (Figure S5C,D, Supporting Information). Here, ACSL4 is linked to head and neck squamous cell carcinoma.