NLRP1 and bronchitis: Critically, human variant mutations in DPP9 (G167S) lead to NLRP1-dependent inflammasomopathies causing immune defects, recurrent fevers, bronchitis, susceptibility to Herpes infections, pancytopenia, anemia, and skin abnormalities34, consistent with NLRP1-mediated inflammation in barrier cells such as keratinocytes and bronchial epithelial cells.