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