IGFBP6 and squamous cell carcinoma: For example, it was shown that the expression level of IGFBP6 in colon cancer cells with a high metastatic potential is lower than in the cells with a low metastatic potential, and the expression of IGFBP6 in secondary squamous cell carcinomas of the head and neck is lower than in primary ones, which indirectly indicates that that IGFBP6 reduces the metastatic potential of tumor cells (Bach, 2015).