For example, a study investigating bladder pain syndrome in Il1b–/– mice showed no improvement in bladder pathology and pain (Butler et al., 2018) while studies in IL-1R–/– mice assessing gout and rheumatoid arthritis did not investigate pathology or pain improvement (Martinon et al., 2006; Vande Walle et al., 2014). The gene discussed is IL1B; the disease is rheumatoid arthritis.