One of the main challenges of cell therapies is the maintenance and/or expansion of the required therapeutic phenotype in vitro. Moreover, to meet both the traceability and safety requirements for a clinical-grade therapeutic, cells need to be cultured in chemically defined conditions. Over the last two decades, scientists have sequenced the genome and epigenome of all known cell types in the human body, in addition to mapping hundreds of possible protein-protein interactions. Joachim Luginbühl and Rodrigo Santos at Mogrify explore epigenetics to systematically optimise culture conditions for cellular therapies.