HHLA2 and cancer: In order to create a good starting point for further investigations aiming to assess regulatory dependencies and genetic interactions between genes and microRNAs, we calculated correlations between all miRNAs and a selected set of 21 genes, known from the literature to be potentially expressed on the cancer side of the immunological synapse: CD112, CD137L, CD200, CD276, CD277, CD40, CD48, CD70, CD80, CD86, GITRL, HHLA2, HVEM, ICOSLG, LGALS9, OX40L, PD−L1, PD−L2, PVR, VISTA and VTCN1.