Recently, the utility of these organoids was demonstrated by introducing mutations in the key driver tumour suppressor genes APC, SMAD4 and TP53, and the oncogenes KRAS and PIK3CA, in colonic organoids via a knock-out/knock-in approach to mimic tumorigenesis according to the classical adenoma-carcinoma sequence model [185, 186]. Here, KRAS is linked to neoplasm.