However, when also considering the PD stage for the grouping of PD patients, only M-PD (130 ± 26 ng/mL, adjusted for covariates, t38 = 3.03, p = .004), but not E-PD (115 ± 19 ng/mL, p > .1) showed significantly increased IGF-1 baseline levels compared with HC (106 ± 24 ng/mL). The gene discussed is IGF1; the disease is Parkinson disease.