CXCL12 and neoplasm: Then, we focused on the tumor cell and lymphocyte interactions mediated by chemokines and demonstrated that mTEC-like and mcTEC-like tumor cells in TETs could induce DP cell migration for positive selection through CCL25:CCR9 and CXCL12:CXCR3 interactions (Supplementary Fig. 13b and Supplementary Data 4).