CXCL12 and neoplasm: Gene Ontology (GO) enrichment analysis revealed a significant increase of some chemokine family members such as cxcl9, cxcl10, and cxcl12, and notably a cell adhesion factor, CD56 (NCAM, neural cell adhesion molecule) in the PTL-Her2-CAR-T cells isolated from tumor tissues (Fig. 3a), which were validated by quantitative real-time PCR (qRT–PCR) analysis (Fig. 3b).