[[*WISE*]{}]{} archive on the basis of the [[*WGS*]{}]{} properties will be performed once it will be completely available [@massaro12b]. However, the $s_b$ and $s_q$ distributions reported in Figure \[fig:histogram\] strongly suggest that the density of [[*WISE*]{}]{} blazar candidates is low over the sky.

![The distribution of the $s_b$ (black) and $s_q$ (red) parameters for all the 55195 [[*WISE*]{}]{} source within all the ROCs defined for the 313 UGSs analyzed. The vertical lines corresponds to the thresholds for the $s_b$ and $s_q$ parameters to determine the blazar classes (see Section \[sec:association\]).[]{data-label="fig:histogram"}](./histogram.pdf){height="6.0cm" width="9.7cm"}

In Table \[tab:example\] we show three cases of [[*WISE*]{}]{}  sources that have been associated with our procedure to three UGSs. We report both the $s_b$ and $s_q$ values, the [[*WGS*]{}]{} class and the association confidence $\pi$. In this example, the source 2FGL J0038.8+6259 is associated to one [[*WISE*]{}]{} source of a class A, J003818.70+630605.0, that has been selected as a single $\gamma$-ray blazar candidate out of 791 [[*WISE*]{}]{} sources within its SR. The corresponding association confidence $\pi$, expressed in terms of number of sources with an higher $s_b$ or $s_q$ values than J003818.70+630605.0 within the region of comparison and estimated considering 830 [[*WISE*]{}]{} sources, is 2/830.

Similarly, the source 