AFF1 and acute lymphoblastic leukemia: Moreover, they examined the influence of MLL/AF4 on the expression of TERT (telomerase reverse transcriptase) coding for the telomerase protein subunit, and subsequently telomerase activity in t(4;11)-positive ALL, showing that MLL/AF4 through the expression of a specific gene, such as HOXA7 unbalanced TERT expression and accelerated telomere shortening [25].