It is shown that the PASI 75 response rates were 33.1% at week 16 after the use of apremilast at 30 mg twice a day, as compared to 5.3% of patients receiving placebo.513 However, the application of PDE4 inhibitors for the treatment of psoriasis has been hampered by their side effects, such as emesis. This evidence concerns the gene PDE4A and psoriasis.