FCER2 and dysplasia: Evaluation of TLS surrounding dysplasia lesions by H&E staining and IHC of CD8, PD-1, CD21 and CD23 were shown in Supplementary Fig. S1B as representative images; matured TLSs were found to existed beneath the dysplasia lesion with the accumulation of TILs expressing CD8 or PD-1 in both TLSs and dysplasia area.