This review describes the reported risk of IFI in patients receiving a variety of targeted agents for hematological malignancies, including monoclonal antibodies; bispecific T-cell engagers (BiTE), such as blinatumomab; tyrosine kinase inhibitors, including phosphoinositide 3-kinase (PI3K) inhibitors, Bruton’s tyrosine kinase (BTK) inhibitors, and janus-associated kinase (JAK) inhibitors; as well as the B-cell lymphoma 2 (BCL-2) inhibitor venetoclax. The gene discussed is BTK; the disease is hematologic disorder.