Consistently, Huang and coworkers [153] found that Flavonifractor was positively correlated with circulating levels of C5a, IL-1β, IL-6, IL-7, IL-8, and IL-21, while Lachnospiracea_incertae_sedis and Coprococcus were both negatively associated with IL-17A, indicating that changes in the gut microbiota may induce an unbalanced Th1/Th2 or Th17/Treg differentiation and related abnormal cytokine production, typical of PV. Here, IL1B is linked to acquired polycythemia vera.