CD4 and head and neck squamous cell carcinoma: FRC-like fibroblasts colocalised with B-cells and CD4 + T-cells (non-Treg; p < 0.0001), found either in focal areas containing high densities of B/CD4 + cells (non-Treg) (HPV+ve/-ve HNSCC) or occasionally more widespread in two HPV+ve samples (59%/23% total spots) but still colocalising with large numbers of B/CD4 + T-cells (Fig. 3BC; Supplementary Fig. 6A, B, C).