Left panel: redshift distribution of the all 161 sources in CAIXAvar. Although the vast majority of AGN belong to the local Universe z < 0.2, 20 sources in CAIXAvar have z > 1, with 4 objects with redshifts as high as 4. Right panel: redshift distributions of all the sources with at least 1 variable segment (see bold values in Table 2) used hereinafter to study the correlations. Only 3 objects, with at least a variable segment, have a redshift higher than 0.2 and only one have z ≃ 0.9.