PRKG1 and opiate dependence: GO enrichment analysis suggested ITK participated in “Cell activation”, “immune system process”, “regulation of immune system process”, “positive regulation of immune system process”, etc. This result suggested that AC004797.1 and PRKG1-AS1 might participate in regulating immune response in skeletal muscle aging by targeting ITK. OPRD1 associated with opioid dependence is also involved in innate immune system [29].