Intranasal insulin has also been found to provide functional improvement in Parkinson's disease and multiple system atrophy patients, according to this double-blinded placebo-controlled pilot study, conducted by Novak et al. in 2019, on these patients to evaluate the effects of 40 IU insulin or saline OD for four weeks on cognitive and functional performance [39]. The gene discussed is INS; the disease is Parkinson disease.