However, CSF αSyn SAAs have shown high diagnostic performance in confirming LB pathology not only in DLB and PD patients but also in most of those affected by prodromal LBD syndromes, such as Isolated Rapid Eye Movement Sleep Behavior Disorder (iRBD) or mild cognitive impairment due to LBD (MCI-LB) and even in asymptomatic individuals [15, 32, 54, 55]. The gene discussed is PCSK1N; the disease is REM sleep behavior disorder.