Review of the ATHENA/WFI instrumental background and lessons learned from SRG/eROSITA

In this paper, we review the study of the ATHENA/WFI instrumental background carried out thus far at IAAT in the framework of the WFI Background Working Group activities; we summarise the results and their impact on the design of the shielding configuration of the camera; finally, we briefly point out some lessons learned from the in-flight experience of SRG/eROSITA.