GAL and neoplasm: Limitations of this study include the use of only two (systemically healthy and male) PBMC donors, of only two HNSCC cell lines with ‘intermediary’ constitutive expression of galanin, the fact that PBMCs do lacking some immune cell types (most notably neutrophils and platelets) and the absence of other cells from the tumor microenvironment (e.g. fibroblasts).