library_construction_protocol: Laser capture microscopy (LCM) was completed using the Arcturus XT Laser Capture Microdissection System. Individual tumors were identified from the scanned H&E slides. An unstained, 10μm thick section of FFPE tissue was mounted on PEN membrane slides (2μm; Leica). Once tissue was cut, forceps were used to pick out dissected tissue from the slide and place in 1.5mL microcentrifuge tubes for DNA or RNA extraction. Following PCR amplification (primers listed in Table 1 in the supplemental methods), amplicons were sequenced using the Illumina Nextera XT kit following the manufacturer's protocol (Illumina). Briefly, following the quality control screening of 100ng of each amplicon on a 1% agarose gel, both amplicons for each sample were pooled equimolar and 1ng of input DNA was used for the Nextera tagmentation reaction, followed by PCR amplification and sample indexing. The libraries were purified, quantitated with the Qubit Fluorometer (ThermoFisher Scientific), and screened on the Agilent TapeStation 4200 using the TapeStation High-Sensitivity D1000 Screen Tape (Agilent Technologies). The final libraries were normalized, denatured, and sequenced on the Illumina MiSeq sequencer using a Nano flow cell to generate approximately 20,000 150-base read pairs per sample.