GN can also be caused by antigen-specific T cells without secreted autoantibodies in experimental anti-GBM nephritis, in which the transfer of activated a3NC1-specific CD4 T cells to naïve rats caused crescentic glomerulonephritis.[20] Autoreactive T cells can subsequently prompt autoreactive B cells, which present the same T-cell epitope of endogenous autoantigens during B-cell epitope spreading, to mount a humoral response. Here, CD4 is linked to crescentic glomerulonephritis.