(a) PiggyBac single vector design for expression of dCas9 and effector cassettes. (b) Binding sites of Sp sgTRE3G on the pTRE3G promoter. (c-f) Fluorescence quantification after 48 h induction for HEK293T pTRE3G-EGFP cells transfected with Sp TRE3G and (c) rapamycin-inducible, (d) PHYB/PIF red light-inducible, (e) CRY2PHR/CIBN blue light inducible, or (f) FKF1/GI blue light-inducible VPR-Sp dCas9. The data are displayed as mean ± SD for two (d-f) or four (c) independent transfections performed in technical replicates (n = 4 or 8). (* P < 0.05, ** P < 0.01, *** P < 0.001, n.s. = not significant, Games-Howell post-hoc test following Welch’s ANOVA).