MED12 and neoplasm: Previous genomic studies of LM have identified MED12 as the most frequently mutated gene in these lesions, but these studies did not report on other recurrent somatic mutations in these tumors.12-14 However, MED12 mutations have been reported also in a subset of LMS tumors, and therefore these mutations cannot be used for a molecular distinction between LM and LMS.15 To investigate whether LM tumors might have recurrently mutated genes other than MED12, we performed whole-exome sequencing on 36 pairs of matched tumor and normal DNA specimens from patients with LM.