In this study, we clarified the significance of LAT1 expression in cancer progression in database analysis and clinical specimens and demonstrated the utility of JPH203, in vitro and in vivo, using a unique stroma-abundant allogeneic immunoreactive mouse colorectal tumor created by the orthotopic transplantation of a mouse-derived CRC cell line and mesenchymal stem cells into mouse cecum. The gene discussed is LAT; the disease is colorectal neoplasm.