We have used single molecule fluorescence in situ hybridization (smFISH) to study cell-to-cell heterogeneity of messenger RNA (mRNA) copy numbers for human host cells subject to a variety of external stimuli. In order to study the effect of various stimuli and genetic modifications on mRNA copy number, we have constructed an automated highthroughput multiplexed imaging system and data analysis package capable of localizing large numbers of individual mRNA transcripts in three dimensions. These experimental distributions of mRNA are used to refine and down-select regulatory models. Here we present a case example of Interleukin 1 alpha mRNA production in response to immune system stimulation. We propose a methodology for extending these methods to study the effect of small RNA on genetic expression by combining multiplexed imaging and numerical modeling at the system-level.