Growth factor of the TGF-beta superfamily that plays essential roles in many developmental processes, including neurogenesis, vascular development, angiogenesis and osteogenesis (PubMed:31363885). Acts in concert with PTHLH/PTHRP to stimulate ductal outgrowth during embryonic mammary development and to inhibit hair follicle induction (By similarity). Initiates the canonical BMP signaling cascade by associating with type I receptor BMPR1A and type II receptor BMPR2 (PubMed:25868050, PubMed:8006002). Once all three components are bound together in a complex at the cell surface, BMPR2 phosphorylates and activates BMPR1A. In turn, BMPR1A propagates signal by phosphorylating SMAD1/5/8 that travel to the nucleus and act as activators and repressors of transcription of target genes (PubMed:25868050, PubMed:29212066). Can also signal through non-canonical BMP pathways such as ERK/MAP kinase, PI3K/Akt, or SRC cascades (PubMed:31363885). For example, induces SRC phosphorylation which, in turn, activates VEGFR2, leading to an angiogenic response (PubMed:31363885). Homodimer; disulfide-linked (By similarity). Interacts with GREM2. Part of a complex consisting of TWSG1 and CHRD. Interacts with the serine proteases, HTRA1 and HTRA3; the interaction with either inhibits BMP4-mediated signaling. The HTRA protease activity is required for this inhibition (By similarity). Interacts with SOSTDC1. Interacts with FBN1 (via N-terminal domain) and FBN2 (PubMed:18339631). Interacts with type I receptor BMPR1A (PubMed:8006002). Interacts with type II receptor BMPR2 (PubMed:29212066). Interacts with FSTL1; this interaction inhibits the activation of the BMP4/Smad1/5/8 signaling pathway (PubMed:29212066). Interacts with SCUBE3 (PubMed:33308444). Expressed in the lung and lower levels seen in the kidney. Present also in normal and neoplastic prostate tissues, and prostate cancer cell lines. The disease is caused by variants affecting the gene represented in this entry. The disease is caused by variants affecting the gene represented in this entry. Belongs to the TGF-beta family. Bone morphogenetic protein 4 entry