The purpose of this study was to test the efficacy of specific phospho-tau monoclonal antibodies-[CP13 (pSer202), RZ3 (pThr231) and PG5 (pSer409)] for efficacy in preventing and clearing tau pathology in the JNPL3 transgenic mouse model of tauopathy. The monoclonal antibodies used included two different phospho-tau Abs targeting phosphorylations appearing on tau from both normal adult brain and PHF-tau,CP13 (pSer202), RZ3 (pThr231), plus a phospho-tau Ab directed specifically to PHF-tau, PG5 (pSer409). As expected not all the antibodies exhibited the ability of reducing tau pathology. In fact, only CP13 was able to lower insoluble or soluble tau accumulation and tau phosphorylation in cortex and hindbrain. It is important to note that treatment with PG5 caused a general remarkable accumulation of soluble and insoluble tau levels in the cortex and hippocampus. The author concluded that while some generalizations may now be possible about which tau epitopes to target, there is a real need to examine multiple different mouse models and examine dose-response relationships for antibodies that appear efficacious.