IL1B and Parkinson disease: In addition, IL-1β gene polymorphisms have been associated with age-at-onset of sporadic PD (Nishimura et al., 2000; McGeer et al., 2002; Wahner et al., 2007), although not all reports lead to similar conclusions (Nishimura et al., 2000; Liu et al., 2010; Pascale et al., 2011; Chu et al., 2012).