MT-I/II-positive macrophage-like cells in stroma (Figs. 3 and 4 A, B) probably contributed to these events since in different types of squamous cell carcinoma and in breast adenocarcinoma, it has been shown that the expression of MT-I/II in cancer-adjacent stroma might reduce the number of CD56- and CD57-positive lymphocytes and contribute to immune system inhibition and tumour progression [32], as well as that zinc and MT might play crucial roles in NK and NKT cell development and functions [50]. Here, NCAM1 is linked to squamous cell carcinoma.