EXOSC2 and retinitis pigmentosa: Recently, Yang et al., used a pool of primary human keratinocytes to study the effect of mutations in the EXOSC2, a gene encoding for one cap protein in the RNA exosome (RRP4) and associated to SHRF syndrome (short stature, hearing loss, retinitis pigmentosa and distinctives facies), which is a novel syndromic form of IRDs [42,94].