contain the biochemical effects of the interactions?
The effect of a signaling interaction can be activation or inhibition. For interactions with indirect evidence, + + and – – mean activation, while + – and – + mean inhibition. A unidirectional interaction (A and B interact as either A → B or B → A) can have only one of these two effects, and for the few bidirectional interactions (A → B and B → A are both possible) there can be more than one type of effect between the two proteins.
