These include the following: CRHR1, associated with budesonide, fluticasone and triamcinolone with a very low evidence level, CYP3A4 associated to tacrolimus with a low evidence level, LTC4S associated to aspirin with a very low evidence level, ADRB2 associated with salbutamol with a low evidence level, CRHR2 associated with salbutamol with a low evidence level, and CYP3A5 associated with several drugs, none of which are used in asthma. This evidence concerns the gene CYP3A4 and asthma.