The subsequent multivariate logistic regression analysis identified age (p < 0.001), bacterial infection (p = 0.005), MYOACT score (p = 0.009), IL-17A (p = 0.017), anti-SRP antibody (p = 0.011) and steroid monotherapy (p = 0.001) as clinical or laboratory factors that were significantly associated with development of PAH in IIM patients (Table 1). The gene discussed is IL17A; the disease is bacterial infectious disease.