RSPO1 and neoplasm: The suppressive effects of KYA1797K on the stemness of small intestinal tumors were also confirmed in ApcMin/+/KrasG12DLA2 mouse model and its small intestinal tumor cell-derived tumor organoids in the presence of EGF, Noggin, and R-spondin-1 which mimics the hyper-activation conditions of LGR5+ CSCs in vivo.