Since there are data indicating that circulating, antigen-reactive, memory T cells, generated by previous sensitization to organic antigens, migrate into lung parenchyma in response to chemokines such as RANTES [18], it is possible that the interplay of CXCL10 with CCL5 may serve to finely tune inflammatory responses in vivo in HP lungs. The gene discussed is CCL5; the disease is hypersensitivity pneumonitis.