Multiobjective Optimization: Defining the Objectivive Function

I am working with a set of genes, whose expression varies in health and diseased condition. I have a regulatory network in which these genes are embedded. I want to optimize the system from a diseased state to a healthy state. Currently using NSGAII optimization

How should i then define the objective function??? I have the time series data of the network and the parameter values.

Please help me out