Figure 2. Cellular clock genes adjust to new time zones at different rates in different body organs.

(A) In the central brain clock, the SCN, Per1 and Per2 lead the system in shifting. (B) Conversely, in the pancreas, Nr1d1 appears to take the lead. (C) The liver circadian clock shows an intermediate pattern. Red indicates genes slower to adjust to jet lag, and green denotes genes faster to respond, as indicated by Kiessling et al. (16).