STRING 9.05 
SMAD4 [ENSP00000341551]
SMAD family member 4; Common mediator of signal transduction by TGF-beta (transforming growth factor) superfamily; SMAD4 is the common SMAD (co-SMAD). Promotes binding of the SMAD2/SMAD4/FAST-1 complex to DNA and provides an activation function required for SMAD1 or SMAD2 to stimulate transcription. May act as a tumor suppressor
UBE2I [ENSP00000324897]
ubiquitin-conjugating enzyme E2I (UBC9 homolog, yeast); Accepts the ubiquitin-like proteins SUMO1, SUMO2, SUMO3 and SUMO4 from the UBLE1A-UBLE1B E1 complex and catalyzes their covalent attachment to other proteins with the help of an E3 ligase such as RANBP2 or CBX4. Essential for nuclear architecture and chromosome segregation
Evidence suggesting a functional link:
Neighborhood in the Genome:  
none / insignificant.
Gene Fusions:  
none / insignificant.
Cooccurence Across Genomes:  
none / insignificant.
none / insignificant.
Experimental/Biochemical Data:   yes (score 0.936).  
Association in Curated Databases:   yes (score 0.900).  
Co-Mentioned in PubMed Abstracts:   yes (score 0.175).  
Combined Score:
Evidence for specific actions:
Binding:yes (score: 0.992)