CXCL12 and B-cell chronic lymphocytic leukemia: In CLL, T cells exhibit significantly reduced LFA-1 expression or impaired LFA-1 function, leading to their failure to adhere to and transmigrate across VCAM-1, ICAM-1, and CXCL12-expressing endothelium, which results in diminished trafficking to lymph nodes (83, 84).