An 83‐year‐old gentleman with history of chronic lymphocytic leukemia (CLL) characterized by multiple cytogenetic abnormalities (trisomy 12, loss of 13q14.2 and 13q34, and loss of TP53) received prior chemotherapy (CHOP‐R and BR) 4 years ago presented with pancytopenia (white blood cells 1.2 × 109/L, hemoglobin 72 g/l, platelet count 30 × 109/L) while on ibrutinib 420 mg orally daily. Here, TP53 is linked to B-cell chronic lymphocytic leukemia.