Thus, U1 snRNA mutations have been associated with medulloblastomas, U2 SF3B1 mutations with blood cancers such as myelodysplasia or lymphocytic leukaemia, U5 Prp8 mutations with retinitis pigmentosa [57,59] and QKI downregulation with lung cancer [58]. The gene discussed is SF3B1; the disease is medulloblastoma.