Th2 cytokines IL-4, IL-5, and IL-9 were evaluated in the ALF in three groups of patients: acute phlegmonous appendicitis (APA), acute gangrenous appendicitis (AGA), and the control group, which is comprised of patients that have a clinical diagnosis of AA and were submitted to appendectomy, but had a normal histology (negative appendicitis) [47]. This evidence concerns the gene IL9 and appendicitis.