Fig. 4
From: Database application model and its service for drug discovery in Model-driven architecture
Domain model. There are 6 domain objects. There are 3 association links among a Drug object, a Gene object, a Disease object and a SideEffect object. There are 2 aggregation links between a Drug object and an ATC object, and between a Gene object and a SNP object. The notation 0..* in the diagram means “zero to many”. And the notation 1..* in the diagram means “one to many”