Gene expression profiling of muscle biopsies from IIM patients in combination with a machine-learning algorithm showed that the novel gene markers CAMK1G (calcium/calmodulin-dependent protein kinase IG), EGR4 (early growth response protein 4), and CXCL8 (interleukin 8) were only present in ASS. Here, EGR4 is linked to acquired idiopathic inflammatory myopathy.