In a series of 349 CLL patients, Rigolin et al. (2021) found that SLAMF1/CD150 downregulation was significantly associated with numerous adverse prognostic factors including highly complex karyotypes, advanced Binet clinical stage, CD38 positivity, high beta2-microglobulin levels, immunoglobulin heavy chain variable region gene (IGHV) unmutated status, 11q deletion, tumor protein p53 (TP53) disruption, and higher risk CLL-International Prognostic Index (CLL-IPI) categories. This evidence concerns the gene TP53 and B-cell chronic lymphocytic leukemia.