To analyse the alteration in CD14 levels and its association with CD14 (−159 C/T) SNP (rs2569190) in Caucasian adults with stable allergic asthma, we performed a cross-sectional study (277 healthy subjects vs. 277 patients) where clinical parameters, CD14 values and the CD14 (−159 C/T) SNP were studied. The gene discussed is CD14; the disease is allergic asthma.