MIXL1 and atrial septal defect: The plasma CPSI level in Mix-PAH patients (230.1 ± 28.18 pg/ml, n = 21; P = 0.000 by ANOVA compared with control group) and Mix patients (165.0 ± 23.17 pg/ml, n = 21; P = 0.000 by ANOVA test compared with control group) was significantly lower than that in normal controls (431.8 ± 41.42 pg/ml, n = 37; Fig. 2), although similar to the ASD patients, there was no significant difference between Mix-PAH patients and Mix patients (P = 0.15 by ANOVA).