GATA2 deficiency is a rare genetic disorder affecting blood cell formation, the immune system, and the lymphatic system that increases the risk of infections and hematologic tumors. The article describes two cases of Palestinian GATA2-deficient siblings, one with Hodgkin's lymphoma and the other with cryptogenic organizing pneumonia (COP), rare manifestations of this disorder. The first patient was mistreated for tuberculosis and later diagnosed with Hodgkin's disease, from which he eventually died. The second patient had recurrent skin infections and respiratory problems, with CT confirming COP, which completely improved after corticosteroid treatment. These cases demonstrate the diversity of clinical manifestations of GATA2 deficiency and highlight the importance of early genetic testing in patients with unexplained cytopenias, recurrent infections, or atypical lung disease. Treatment of GATA2 deficiency is difficult, with hematopoietic stem cell transplantation being the only curative option. An incorrect diagnosis can lead to inappropriate treatment and poor results. Further research is needed to better understand the links between GATA2 mutations, lymphoproliferative and lung diseases[1][4].