<prompt> Most common subtype of adult ALL?B- lineage ALLPre-B- ALLT-lineage ALLCoical T-ALL  <response>: ALL is the most frequent neoplastic disease in children with an early peak at the age of 3-4 years More than 70 of adult ALLs are of B-cell origin, and the most frequent immunological subtype, common ALL, is characterized by the presence of ALL antigen, a glycoprotein gp100CD10. Pro-B-ALL also termedearly B-precursor ALL is a leukemia that was formerly termednon-T,non-B-ALL, ornull-ALL as neither T-cell nor B-cell features could be demonstrated. This subtype forms about 11 of adult ALL. Approximately 25 of adult ALL belongs to the T-cell lineage. All cases express the T-cell antigen gp40, CD7 and cytoplasmatic or surface CD3. They may, according to their step of T-cell differentiation, express other T-cell antigens, e.g., the E-rosette receptor CD2 andor the coical thymocyte antigen T6 CD1. A minority of T-ALL blast cells may also express common ALL antigen together with other T-cell antigens. According to these markers, it is possible to distinguish a pro-T-ALL also termedearly T-precursor ALL, coical, or thymic T-ALL and a mature T-ALL expressing different stages of differentiation. 