We identified all major stages of B cell maturation in HNSCC, including naive B cells (cluster 1), memory B cells (clusters 2 and 3), tissue-resident Fc receptor like 4 positive (FCRL4+) B cells (cluster 4), GC B cells (cluster 5), ISG B cells (cluster 6), and plasmablasts (cluster 7), and plasma cells (clusters 8 and 9) (Fig. 4b). Here, FCRL4 is linked to head and neck squamous cell carcinoma.