This study involved an exploration of the effects of FZHFZY on epidermal differentiation and its underlying mechanisms in interleukin (IL)-17A/IL-22/interferon (IFN)-γ/tumour necrosis factor (TNF)-α–stimulated HaCaT cells and in a mouse model of imiquimod (IMQ)-induced psoriasis. This evidence concerns the gene IL22 and psoriasis.