Tumours developed in the right colon are characterized by a downregulation of genes involved in ribosome pathway (RPL10, RPL10A, RPL12, RPL13, RPL14, RPL17, RPL21, RPL22, RPL2,6 RPL35A, RPL37A, RPL38, RPL39, RPL5, RPL6, RPS11, RPS15, RPS1,9 RPS21, RPS4X, RPS5, RPS9) matched to tumours developed in the left colon (Table S5A). The gene discussed is RPS21; the disease is neoplasm.