In our previous work, we have shown that the expression of OPN and MMP9 were positively correlated in human bladder cancer specimens and bladder cancer cell lines.12 In the present study, we found that overexpression of OPN up‐regulated MMP9 while OPN and MMP9 expression levels were positively correlated in two independent colon cancer datasets. This evidence concerns the gene SPP1 and malignant colon neoplasm.