Compared to the primary appendix site, the metastatic tumors had differential expression of the following genes: TCN1 which encodes the transcobalamin 1 protein that binds the B12 vitamin and is associated with poor prognosis and metastasis in colon cancer (Liu et al., 2020); the goblet cell marker WFDC2; GNAS which is a driver of appendiceal cancer (Supplementary Figure S6C). This evidence concerns the gene GNAS and metastatic neoplasm.