The patient's symptoms fit some of the criteria for the diagnosis of ANCA-associated vasculitis (PR3 positivity with ANCA antibodies, lung cavitations, and obstructive air disease on presentation along with eosinophilia - 2022 ACR/EULAR); however, those were not sufficient for a definitive diagnosis based on current definitions [17]. The gene discussed is PRTN3; the disease is Increased total eosinophil count.