I'm doing some research on tau protein phosphorylation. When I'm looking for antibody of pTau T217, I just found antibodys(ELISA Kits) of pTau T534 saying it's for pTau T217. I searched NCBI protein database, microtubule-associated protein tau isoform 2 [Homo sapiens] with full length of 441 have the Thr on 217 which is the same with what I learned from school. But why there is a T534? Are they the same?