The Phytophthora infestans-tomato interaction is a good example where the transcriptome and metabolomes have been integrated, to derive a robust infection model [121]. Predictive genome-scale metabolic models (GEMs) were derived from P. infestans enzyme sequences, which were related to KEGG metabolic networks [122]. This GEM was then improved by incorporating further information, such as organellar location and, crucially, transcriptomic and metabolomic **data** [121]. These models showed how P. infestans growth was dependent on host thiamine biosynthesis. Moreover, separate consideration of the host and oomycete transcriptomic **data** showed how the pathogen increasingly shuts down some of its own biosynthetic pathways, becoming more dependent on host-sourced nutrients. Although undoubtedly challenging, such multi-omic approaches offer the possibility of major new insights.