MACC1 and neoplasm: However, the role of plexin B1 remains controversial because in various cancers, both tumor-promoting and tumor-suppressing effects have been observed.278–280 A recent study found that a newly identified gene, MACC1 (metastasis-associated in colon cancer 1), has high potential to be a key regulator of MET expression and further influence CRC progression and metastasis.281 Elevated levels of MACC1 expression were found in both local and metastatic malignant tissues.