The National Comprehensive Cancer Network guidelines recommend the use of zanubrutinib as a first-line or second-line therapy for patients with CLL/SLL with del(17p)/TP53 mutations who have a contraindication to other BTK inhibitors, and as second-line and subsequent therapy for patients without del(17p)/TP53 mutations who are intolerant of, or have a contraindication to, other BTK inhibitors (61). This evidence concerns the gene TP53 and B-cell chronic lymphocytic leukemia.