Abstract Distant metastasis is the major determinant of patient outcome in colorectal cancer. By systematically analysing the miR expression profiles of resected metastasis-, corresponding primary tumor and normal tissues of colorectal cancer patients, we were able to delineate a miR-signature indicative of the metastatically critical microRNA landscape. This “hot list” of miRNAs, including established metastasis-related miRs like the miR-34- and let -7 families, as well as rather novel miR-candidates like miR-552, -218, -135, -210 and -654, together with their putative common targets were bioinformatically predicted to regulate the most significant metastasis-associated signaling pathways currently known. We were able to show for the first time that miR-135b, miR-210 and the loss of miR-218 constitute a novel network that regulates both E- and N-cadherin expression, which is achieved, in part, via several novel common targets such as the recently described tumor suppressors SIAH1 and SETD2, and, most importantly, FOXN3 transcription factor. This is paralleled by a significant impact on migration, invasion, in vivo intravasation and metastasis in chicken embryo and mouse models. We conclude that miR-218 as a novel metastasis suppressor, and pro-metastatic miR-135b and miR-210, constitute one important novel network critical for metastasis, resulting from the first study to systematically suggest the microRNA-driven master pathways of metatasis from solid cancer tissues. Citation Format: Giridhar Mudduluru, Mohammed Abba, Jasmin Batliner, Nitin Patil, Taral R. Lunavat, Maike Scharp, Jörg Leupold, Olga Oleksiuk, Ivo Buchhalter, Wilko Thiele, Melanie Rothley, Axel Benner, Jonathan Sleeman, Heike Allgayer. A systematic approach to the metastatically relevant microRNA landscape. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 1443. doi:10.1158/1538-7445.AM2014-1443