KRAS and neoplasm: The KRAS and BRAF mutations were detected at an allelic fraction of 22-31% in the right ovary and 3-7% in the left ovary respectively, hence the clonal population containing an undetected driver mutation could have already been present in some or all of the tumor samples at primary debulking; expansion/recurrence of this population could then explain the absence of mutant KRAS/BRAF in the recurrent setting.