External validation.

nc: non correctly classified
1Number of the genes of our 33 gene signature present on the used platform.
2Number of samples correctly classified using our signature (restricted to the number of genes in column “Nb genes”).
3Genes in common between our 33 gene signature and those published in each study (Table 2 in Ki, Supplementary Table 2 in Koh, Fig. 2 in Kleivi, Supplementary Table 2 in Lin).
4Ten of the CN samples are from the 13 paired patients used to identify the 34-probe signature.
5CT and CP are not clearly separated and are in a single class (Fig. 3).
6LN and LM clustered in independent groups but were not separated from CT (Fig. 3).
727 CT with synchronous and 20 CT with metachronous metastases.
812 rectum and 3 colon tumors.
9HM and LM are not separated and are in a single class.
108 right and 5 left colon tumors. 5 rectum tumors.
11Only SPP1 is in the top 35 ranking genes in Lin's study (Fig. 1 in Lin).