Colorectal liver metastasis (CRLM) is a global public health burden and chemotherapeutic resistance remains a major challenge in the clinical management of these lesions. While the growing use of immune checkpoint inhibitors has highlighted the potential for durable clinical responses upon reinstatement of antitumour immunity, existing T cell-directed immunotherapies are ineffective against most CLRM due to low tumour mutational burden. Natural Killer (NK) cells offer an innate source of cellular cytotoxicity that may be leveraged against poorly antigenic cancers, but the factors limiting their activity in CRLM are poorly characterised. In this study, we employed transcriptomics and functional approaches to identify small molecules that synergise with standard-of-care chemotherapy to enhance NK cell-mediated cytotoxicity against preclinical models of CRLM. Tissue specimens were collected from patients undergoing surgical resection of CRLM following neoadjuvant chemotherapy and these were subjected to whole-transcriptome sequencing. Unsupervised clustering of tumour transcriptomes revealed three groups exhibiting a stepwise increase in pan-immune and NK cell-specific signature scoring. The most immunologically extreme groups were subsequently compared to interrogate putative mechanisms underpinning the divergent immunological phenotypes. Immunologically-cold CRLM samples were highly enriched for signatures previously associated with chemotherapeutic resistance in CRLM, particularly cell cycle regulation and DNA replication and repair. Given these observations, we evaluated the immunoregulatory potential of compounds targeting master cell cycle regulators using a three-dimensional in vitro co-culture model combining NK cells and patient-derived tumour organoids (PDTOs). Preliminary examination of 44 compounds targeting 13 cell cycle regulators was performed to survey single-agent activity and augmentation of NK cell-mediated cytotoxicity against three PDTOs derived from immunologically-cold CRLM. We found that compounds targeting the spindle-assembly checkpoint or mitotic machinery were most synergistic with NK cell co-culture, consistent with reports that experimental induction of chromosome mis-segregation drives inflammatory signalling and promotes immune clearance. We are now evaluating the immunoregulatory effect of top-performing compounds for all targets when co-administered with standard-of-care chemotherapy. These findings suggest that tumour cell-intrinsic mechanisms facilitating survival during treatment may also limit antitumour immunity and that inhibition of cell cycle regulators may exert cytotoxicity via both tumour cell autonomous and immune-mediated mechanisms.