(A) Representative western blot of HTT (ab-MAB5492), HTT pS13 (ab-CHDI-90001039-1) and HTT pT3 (ab-CHDI-90001528-1) upon coexpression of HTTex1 16Q eGFP, mutants with S to A substitutions at T3 or S13/S16 or HTTex1 72Q eGFP with TBK1 or TBK1 kinase-dead (KD) for 48 hour in HEK293T cells (the additional high molecular weight HTTex1 and HTT pS13 band is possibly due to the co-occurrence of phosphorylation at both S13 and T3). (B) Quantification of the fold changes in the HTT pS13 (upper panel) and pT3 (lower panel) ratio to total HTT compared to those of the kinase-dead mutant from the experiments like in A (n=3). 