Hoi Hin Kwok's primary research interest is thoracic oncology, with a laboratory focus on translational studies of intratumoural heterogeneity, tumour immunology, and liquid biopsy in lung cancer and malignant pleural mesothelioma. They previously identified drug-tolerant persister subpopulations of ALK-rearranged lung cancer cells enriched in IL-17 signalling. These cells secrete CCL20, exhibit stem-like features, and are associated with Th17 infiltration and poor survival, suggesting that CCL20-mediated Th17 recruitment promotes immune evasion and resistance. We also showed that anti-CCL20 treatment can resensitise tumours to anti-PD-1 therapy in immune-cold, EGFR-mutant lung adenocarcinoma by remodelling spatial T-cell interactions. Currently, they are investigating the spatial heterogeneity of malignant pleural mesothelioma using deep-multiplex immunohistochemistry and spatial transcriptomics in both animal models and human specimens, focusing on the interactions between tumour-associated macrophages, fibroblasts, and malignant cells within the tumour microenvironment.