IL4 and retinitis pigmentosa 1: In previous studies, Yoshida and coworkers showed that: i) inflammatory cells accumulate in the vitreous cavity of RP patients, mainly younger ones; ii) RP patients with increased inflammatory cells into vitreal cavity show decreased visual function; iii) increased proinflammatory cytokines and chemokines (IL-1α, IL-1β, IL-2, IL-4, IL-6, IL-8, IL-10, IFN-γ, GRO-α, I-309, IP-10, MCP-1, MCP-2, and TARC) typify both aqueous and vitreous from RP patients (Yoshida et al., 2013).