A shortlist of candidate tumour endothelial markers was generated by Microarray comparison of differential gene expression between multiple patient-matched colorectal cancer and normal colon samples. This list was narrowed through a process of literature review, real-time quantitative polymerase chain reaction and immunohistochemistry. Through siRNA knockdown and analysis in in vitro models of angiogenesis, it has been demonstrated that a decrease in an novel target’s expression significantly decreases cellular migration, communication and chemotaxis, without adversely affecting cell viability or proliferation in HUVEC. Vaccination with a murine Fc fusion protein in combination with Freund’s adjuvant stimulated a specific immune response to this self-antigen, by breaking immune tolerance. The resulting increase in specific IgG1 antibody titers, indicative of Th2 T-cell response, resulted in a significant reduction in physiological angiogenesis in the subcutaneous sponge assay, and a significant decrease in colorectal tumour growth in a murine subcutaneous CT26 tumour model. The gene of interest represents a novel tumour endothelial marker in colorectal cancer. A hypothesised mechanism for the observed effects is an inhibition of endothelial calcium influx, leading to decreased angiogenic potential in tumour endothelial cells.