ZDHHC13 and Huntington disease: Subsequently, in immortalized cell lines and primary neurons carrying the palmitoylation-resistant mutation HTT (C214 to serine, C214S) and in a YAC128 mouse model (full-length human HTT transgenic mice with 128 CAG repeats), it was demonstrated that zDHHC17 and zDHHC13-associated palmitoylation are both decreased in HD, increasing susceptibility to excitotoxicity (Singaraja et al., 2002).