DCF/LCCF correlation test results of the long-term radio and optical data, radio and HE gamma-ray data, and optical and HE gamma-ray data. The time lags found for each data set pair were −160 ± 11, −140 ± 13 and 20 ± 12 days. A negative time lag implies that the higher-energy band is leading the lower-energy band and a positive one the opposite. The solid green, dotted orange, and dashed red lines show the 1σ, 2σ, and 3σ significance levels, respectively.