However, this may underestimate the rate of paraneoplastic cases, given that (a) the tumour status was unknown in some patients, that (b) neurological manifestations may precede tumour diagnosis by many years in patients with paraneoplastic neurological disorder (PND) (as was indeed the case in one of the ITPR1-IgG/anti-Sj-seropositive index patients), and (c) that the underlying tumour not uncommonly remains occult in PND, often being found only upon autopsy. Here, ITPR1 is linked to neoplasm.