Existence is derived from Exist. Exist is related to Alive. Virus cannot be Alive. you are likely to find Virus in/at/on Body. 
Designer is related to Fashion. Craft is a type of Fashion. Craft is a type of Skill. 
Existence --DerivedFrom--> Exist <--RelatedTo--> Alive <--NotHasProperty-- Virus --AtLocation--> Body 
Designer <--RelatedTo--> Fashion <--IsA-- Craft --IsA--> Skill 