Average null signal calculated using the cross-correlation of the GASS CIB field with 1000 random CMB maps shown in red. The shaded area in yellow spans the 1σ region of the null signal, which is represented by the green lines. The measured CIB×CMB cross-correlation is shown in blue. We also show the CIB×CMB cross-correlation measured using a bin size Δℓ=20 instead of 10 (black points and dashed line).