CD4+ T cells play an integral role in adaptive immune responses. When a pathogen is detected, information is communicated to T cells through antigen presentation. Following activation, naive CD4+ T cells differentiate into one of several lineages of T helper cells (Th1, Th2, Th9, Th17, or Th22), depending primarily on the antigen, the strength of the TCR signal, and the cytokines present in the surrounding extracellular environment. Differentiation of each T cell subset is associated with the expression of specific transcription factors followed by secretion of a defined array of cytokines that orchestrate a directed response to the antigen. The ability to isolate CD4+ T cells and differentiate them into specific T helper cells ex vivo is valuable to researchers who require enriched Th1, Th2, or Th17 cell populations for downstream applications including high throughput assays.