In situ immunolocalization of GPCs and NG2/CSPG4 in oral cavity HNSCC primary lesions. Representative patterns of GPC and NG2/CSPG4 distribution in oral cavity HNSCC lesions. (a, b) representative views of GPC1 expression in lesions with different degrees of keratinizing neoplastic cells. (c, d) representative images of GPC1 expression in stromal cells of pre-malignant lesions (c) and lack of expression in the stromal cells of HNSCC tissue (d). GPC3 was detected in neoplastic cells (e), but not stromal fibroblasts (f), whereas GPC4 (g) and GPC6 (h) were primarily found to be associated with the neoplastic cells. (i) Shows the lack of expression of GPC6 in the intralesional stroma. NG2/CSPG4 was found to be abundantly expressed in both well- (k) and moderately-differentiated (l) oral cavity HNSCC lesions, whereas it was similarly absent from potentially pre-malignant lesions (j).