CCL15 and neoplasm: The expression of a series of G1/S cell cycle‐related genes (CCND1, TP53, CDKN1B and E2F1) and chemokines (CCL15 and CCL20) was higher in tumour areas of TLS‐mature tumours than in TLS‐immature and TLS‐negative tumours (Figure 6A; Table S12), which underlies the characteristics of TLS‐mature tumour cells in the cell cycle and immune regulation.