This also explains why we only found one FGFR1/2 mutation in the extensive additional Sanger screening effort, as a large proportion of HMGA1/2 and PLAG1 tumours had been included in the discovery set of RNA-sequenced samples (MED12 mutations explain for the large majority of all UL cases, and thus, up to 75.3% [2,016/2,677] of ULs in our unselective Finland Myoma Study collection belong to MED12 subtype) [5, 9]. This evidence concerns the gene HMGA1 and benign muscle neoplasm.