We next searched for the molecular signatures of PDGFRα, PDGFRβ, and c-MYC in MBs using the R2 software (http://r2.amc.nl) by assessing the correlations of genes in major pathways with cellular functions in five cohorts of MBs previously determined by microarray from at least more than 45 samples containing all 4 subgroups of clinical MBs [29, 32, 33, 59, 60]. Here, MYC is linked to Mobius syndrome.