Among 495 patients who were immunocompromised and tested positive for SARS-CoV-2, polymerase chain reaction cycle thresholds remained <33 beyond 20 days more frequently in patients with hematologic malignancies, particularly those receiving B-cell–depleting or Bruton tyrosine kinase inhibitor therapy, as compared with those with solid organ malignancy (26% vs 5%). This evidence concerns the gene BTK and hematologic disorder.