CD1C and head and neck squamous cell carcinoma: After comparing our results with an available scRNAseq dataset of HNSCC patients of similar size (n=3) treated with anti-PD-1 monotherapy (17), we saw an increase in dendritic cells associated with T-cell responses and antigen presentation (CD1C+ and CLEC9A+ XCR1+ DCs) in two of three patients.