CD4 and head and neck squamous cell carcinoma: Furthermore, the CGRP KO group exhibited a notable reduction in tumor size relative to the WT mice, indicating that αCGRP signaling can hinder antitumor immune activity.126 Additionally, single-cell RNA sequencing (scRNA-seq) revealed increased expression of RAMP1 in tumor-infiltrating lymphocytes in head and neck squamous cell carcinoma (HNSCC) samples compared to healthy donor palatine tonsil tissues, particularly in CD3+ CD4+ FOXP3– T cells.