I hope to gain insight into novel genetic aberrations present in these patients that will highlightimportant pathways that are involved in this subtype of leukaemia. It would be interesting to see ifthe mutations and pathways that are activated are consistent between the patients, or differencesare observed dependent upon whether the patient has the translocation or the PAR1 deletion. Ofnote is the high association with either numerical gains of chromosome X or numerical/structuralabnormalities of chromosome 21 (Down syndrome, iAMP21) in patients with CRLF2 deregulation. Ihope to find abnormalities linking chromosomes X and 21 to CRLF2 deregulation in BCP‐ALL. Byincluding the three patients that are normal for CRLF2, but have consistent genetic abnormalitiesfound in the experimental cohort, I expect to find genetic differences between these two groupsthat will help us to identify novel molecular targets specific to CRLF2 deregulation.