If CLL cells get activated via CD40–CD40L signaling, then N-linked glycosylations of CD44 take place (particularly associated with the variant isoform CD44v6) and this glycoprotein strongly binds to HA causing CLL cells to stop migrating and instead tightly adhere to HA-bearing stromal cells. The gene discussed is CD40; the disease is B-cell chronic lymphocytic leukemia.