The aims of this study are to (i) investigate the effect of KO supplementation on CRC tumour growth and metastasis in comparison with oxaliplatin treatment; (ii) determine whether the in vivo anti-cancer effect of KO is associated with the mitochondrial death pathway, and (iii) investigate the in vivo effect of KO on the expression of PD-L1, PD-L2, PD-1, and HSP-70. The gene discussed is PDCD1; the disease is neoplasm.