ATIP3 thus appears as a new member of a functional family of microtubule-associated proteins, including adenomatous polyposis coli APC [34], LZTS1 [35] and RASSF1A [31], [36], that interfere with the microtubule cytoskeleton to regulate essential steps of mitosis and have been clearly identified as tumor suppressors down-regulated or mutated in breast cancer. This evidence concerns the gene MTUS1 and neoplasm.