Although sublingual immunotherapy (SLIT) has become an effective treatment option for many allergies, about 20-30 percent of patients don't respond to SLIT for Japanese cedar pollinosis -- a highly common disease. In a recent study, scientists reported that a specific variant of the HLA-DPB1 gene is associated with poor response to this treatment, highlighting the potential of this and similar genes as relevant biomarkers in clinical practice for predicting one's responsiveness to allergen immunotherapy.