- Subjects must be willing to have a biopsy of relapsed disease. Consent will be obtained through the TRACERx study. (TRACERx patients) or using the DARWIN2 trial entry biopsy consent form (non-TRACERx patients). Procurement of the biopsy sample is not necessary at the time of trial registration. However, patients must undergo a biopsy prior to commencement of any trial treatment.