Given that TSLP's primary function is to prime the differentiation of naïve T lymphocytes into Th2 cells via activation of antigen presenting cells [9]–[13], this crucial molecule is now considered the potential missing link between innate antiviral epithelial immunity and the Th2 atopic immune response characteristic of asthma [12], [13]. The gene discussed is TSLP; the disease is asthma.