Collagen COL11A1 was found to be a reliable proxy for the signature: in each solid tumor dataset that we tried, the list of genes whose expression is most highly correlated (using measures such as mutual information [6] or Pearson correlation) with that of COL11A1 consistently includes the other genes of the signature at the top, with the only exception of glioblastoma in which COL11A1 is not as prominently co-expressed with the other genes, though the signature is still present otherwise. This evidence concerns the gene COL11A1 and glioblastoma.