MUC17 and cancer: Among non-driver genes mutated at high frequency in our discovery set (>3 samples, 8%), we detected several known to be hypermutated in many cancer types (TTN, MUC17, MUC16, OBSCN), mostly due to their length (>4,000 codons, with long introns often spanning more than 1 Mb) and believed to primarily harbor passenger mutations (Fig. 1c)14–16.