To address this issue, single-cell RNA-seq data from HNSCC samples of recently published studies could be analyzed in order to assess the association between ESR1 expression and the ESR1-related 25-gene set in malignant epithelial cells versus non-malignant cells and to confirm the potential vulnerability of cancer cells to endocrine treatment at the single-cell level. Here, ESR1 is linked to head and neck squamous cell carcinoma.