IL4 and Eczematoid dermatitis: Piazza et al. investigated the potential of a standardized bark extract against eczema (AD) using human keratinocytes (HaCaT cells) induced with various cytokines including TNF-α (tumor necrosis factor alpha), IL-4 (interleukin 4), and a mixture of TNF-α/IL-4 and TNF-α/IFN-γ (interferon gamma) [64].