Applying the overall median post-operative plasma OPN level (153.02 ng/ml) of CRC patients in this study as the threshold value, CRC patients with high post-operative plasma OPN level were more likely to develop distant metastasis (29 out of the 45 patients) than those with low post-operative plasma OPN level (11 out of 44, p<0.01; Fig 2B). The gene discussed is SPP1; the disease is colorectal carcinoma.