In addition, due to its suppressive role toward p-S6R in both the APC and non-APC mutated setting, the inclusion of RSPO1 in the culture medium for intestinal PDOs needs to be carefully evaluated, especially in preclinical studies assessing the efficacy of Wnt or mTOR inhibitors or investigating the interplay between mTOR and the other molecular pathways underlying CRC carcinogenesis. The gene discussed is RSPO1; the disease is colorectal carcinoma.