Fig. 4.

Proposed model of the role of interleukin 33 (IL-33) in squamous cell carcinoma (SCC) growth via a dual effect on tumour proliferation, migration and invasion, and T cell activation. IL-33 + epithelial and mononuclear cells are found in in the SCC lesions (Fig. 1). The release of this cytokine induces changes in the biology of SCC cells by promoting a pro-tumour phenotype directly (Fig. 2) or indirectly by inducing other factors in the tumour microenvironment (not tested). The neutralisation of IL-33 restricts SCC outgrowth, decreases Th2-derived IL-4 and increases accumulation of Th1 IFNγ-producing cells in tumour-draining lymph nodes (Fig. 3), and thus represents an effective and promising strategy for SCC treatment. Created with Biorender