As it was reported that there are two types of IL-4 receptor, Type I receptor consist of IL4Rα and γ-chain, Type II receptor contain IL4Rα and IL13Rα, thus we further explored the mRNA and protein expression of IL13Rα in early OCPs, unlikely IL4Rα, the mRNA and protein level of decreased significantly once CRC cells went into bone (Fig. 3C, right), indicating that Type 1 IL4 receptor dominantly participated in the bone metastasis of CRC. This evidence concerns the gene IL13RA1 and colorectal carcinoma.