Recognized T-ALL subsets are the following: pro-T EGIL T-I (cCD3+, CD7+), pre-T EGIL T-II (cCD3+, CD7+ and CD5/CD2+), cortical T EGIL T-III (cCD3+, Cd1a+, sCD3+/−) and mature-T EGIL T-IV (cCD3+, sCD3+, CD1a−). Here, CD2 is linked to acute lymphoblastic leukemia.