Microbibrillar-Associated Protein 3-Like (MFAP3L), also known as NYD-sp9, is part of the microfibrillar-associated protein family (MFAPs). MFAPs are non‐fibrillin, extracellular matrix glycoproteins that interact with fibrillin and were originally characterized in microfibrillar assembly (1,2). In humans, there several subfamily members with varying amino acid (aa) sequence homology and functions (1,2). Among the family, MFAP2 and MFAP5 are more closely related and while MFAP1, 3 and 4 share no structural or sequence homology with MFAP2, MFAP5 or with each other (1,2). Human MFAP3L shows 71% amino acid (aa) sequence homology to MFAP3, but not other MFAPs (3). Mature, human MFAP3L consists of an extracellular domain (ECD) containing N-linked glycosylation sites, a transmembrane domain, and a cytoplasmic domain with a conserved SH2 motif (3). The ECD of human MFAP3L shares 89% and 90% aa sequence identity with mouse and rat MFAP3L, respectively. MFAPs have the unique ability to interact with TGF-beta family growth factors, Notch and Notch ligands and multiple elastic fiber proteins, in addition to interacting with fibrillin (1, 2). MFAPs are expressed in a wide variety of tissues and, along with microfibril assembly, they play roles in the regulation of tissue homeostasis, cell survival, and tumor progression (1,2). MFAP3L is often located within colorectal cancer (CRC) cells, which metastasize by activation of the nuclear ERK pathway via MFAP3L phosphorylation (3). Regulation of this MFAP3L activity could have pharmaceutical effects on CRC tumor progression (3).