*IgG4 related Interstitial Lung Disease is the right answer* *There is an urgent need for awareness of IgG4 related disease to achieve earlier diagnoses and better prognosis* *There are several leads suggesting diagnosis of IgG4 disease in this case:* 1) Subacute/ chronic course of disease and fluctuating symptoms, which were very important to differentiate form malignancies; 2) Multiple organ systems involvement (skin, lymph node, lung, bone marrow, etc.,); 3) Profound hyperglobulinemia which indicated an immunemediated pathophysiology; 4) severe interstitial lung disease with no explainable etiology. *#medlung Talks 🫁*