SOCS3 and infection: In the present study, in TL fish the expression of SOCS1 and the IL-6-dependent SOCS3 increased, whereas the expression of STAT1 and STAT3 decreased at the majority of time points post-infection, likely impacting the ability to execute a protective immune response against M. cerebralis. SOCS1 and SOCS3 potentially constrain the expression of STAT1 and STAT3 in TL causing Th17/Treg17 imbalance, leaving fish unable to reduce parasite burden or control inflammatory reactions.