Our results showed that early passages of the PDTT xenograft models of primary colon carcinoma with lymphatic and hepatic metastases revealed a high degree of similarity with the original clinical tumor samples with regard to KRAS, BRAF, EGFR, and PIK3CA mutation status (see Fig. S1, S2, S3, S4) as well as mRNA expression (data not shown). The gene discussed is KRAS; the disease is colon carcinoma.