Four-drug model fitting. The figure shows the model-predicted ATP-levels versus the experimentally obtained values for four drugs combinations. The model used is a four neuron single layer neural network model that was fitting using a data set of size 148 out of 2401 combinations. The correlation between the experimentally tested cellular ATP-level (x-axis) and the predicted cellular ATP-level (y-axis) is shown. The circles in the graphs represent individual data points. The diagonal line represents a perfect fit between the experimental and predicted data.