(A, B, C, D, E) Dose-dependent effect for inhibitors of (A) casein kinase I (CK1d)—LH846 and D4476, (B) CDK2—SU9516, (C) CDK7—BS-181 HCl, (D) serine/threonine-protein kinase 26 (MST4)—Hesperadin, and (E) TRAF2 and NCK-interacting protein kinase (TNIK)—KY-05009 were evaluated. Luminescence rhythms of Per2-dLuc U2OS cells were monitored in the presence of 11 different concentrations of these six kinase inhibitors (threefold serial dilution starting at 100 μM). Period parameter was obtained by the curve fitting and plotted against the final concentration of the compounds (adjusted by keeping the control Per2-dLuc cells period length as 24 h). Dose–response curves showing the circadian period length alterations with the top seven concentrations of the compounds (100–0.14 μM). Data are the representative of multiple biological replicates (n = 4, mean ± SEM). One-way ANOVA, Dunnett’s test. *** indicates P < 0.0001, ** indicates 0.0001 < P < 0.001, and * indicates 0. 001 < P < 0.05.