STRAP (Serine-threonine kinase receptor-associated protein), also known as MAWD, is a ubiquitous WD40 domain protein, common function of which is to provide a suitable scaffold for coordinating multiprotein complex assemblies and thus, regulate a variety of cellular processes like signal transduction, transcriptional regulation, programmed cell death and so on. STRAP plays a role in the cellular distribution of the SMN complex, which is essential for spliceosomal snRNP assembly in the cytoplasm. STRAP inhibits transforming growth factor-beta (TGF-beta) signaling and enhances tumorigenicity via TGF-beta-dependent and -independent mechanisms. STRAP is up-regulated in several cancers and functions as an oncogene. STRAP imparts oncogenic characteristics to cells by promoting ERK and pRb phosphorylation. Moreover, STRAP regulates c-Jun stability by decreasing the ubiquitylation and proteosomal degradation of c-Jun.