Expression profiles of different proNGF/NGF mixtures at 15 minutes. The figure shows the behaviour of genes in five different experimental conditions, 15 minutes after the treatments. Each single line plot is composed by 5 experimental points, respectively: 20 ng/ml proNGF, 10 ng/ml NGF, proNGF/NGF = 20/10 ng/ml, proNGF/NGF = 40/10 ng/ml, proNGF/NGF = 200/10 ng/ml. Expression profiles have been grouped based on two criteria: i) the responses to single NGF and proNGF ligands are similar or different ii) the shape of the response to mixtures and their similarity to the response to ligands alone. A) Response to NGF or proNGF alone: similar. Response to mixtures: variable depending on the proNGF/NGF ratio; left: first cluster of response profiles; right: second cluster of response profiles, with a saturation effect with proNGF/NGF increasing ratio. B) Response to NGF or proNGF alone: different. Response to mixtures: similar to proNGF. C) Response to NGF or proNGF alone: different. Response to mixtures: similar to NGF. D) Response to NGF or proNGF alone: different. Response to mixtures: variable depending on the proNGF/NGF ratio; left: response to NGF alone > proNGF; right: response to NGF alone < proNGF. The notes on the right summarize the prototypical responses to the single neurotrophins and to the mixtures. Colours of treatments (blue, orange, green) are the same as Figure 6.