Fig 3.

(A) Rare KRAS-mutant (mut) clones were detected in a validated cohort of BRAF V600E–mutant colorectal cancer tumors by droplet digital polymerase chain reaction (ddPCR). (*) Lower limit of detection for clinical sequencing is approximately 5% to 20% depending on assays used. (†) Lower limit of detection for ddPCR. (B) A patient-derived xenograft model developed resistance to vemurafenib analog PLX4720 provided through ad lib chow at a dose of 417 mg/kg. Gray represents control arm; blue and gold represent PLX4720 treatment arm with acquisition of KRAS G12R and G12D mutations, respectively.