Subtyping: What It is and Its Role in Precision Medicine

Precision medicine is an emerging approach that considers variability in genes, environment, and lifestyle in order to better treat individuals. This article gives an overview of the diverse approaches to subtyping, from early accounts based on clinical practice to more recent approaches that focus on computationally derived subtypes based on molecular and electronic health record (EHR) data. This field is expansive and growing rapidly; the authors juxtapose approaches taken by different communities and highlight examples of significant open computational problems.