IGFBP2 and pulmonary arterial hypertension: When we studied subtypes of PAH, IGFBP2 was significantly associated with APAH-CTD in both JHPH and PAHB cohorts (rank sum p < 0.0001 for both cohorts); using logistic regression analysis after adjusting for age and sex, the significant association was only found in the PAHB cohort (coefficient 0.958, p = 0.001) (Tables 3 and 4).