A strong enrichment was also observed for the proto-oncogenes FBJ osteosarcoma oncogene (Fos) and Jun (Jun), two TFs known as immediate early genes (IEGs), a group of TFs that also includes the previously identified epilepsy-associated TF Egr1 (Figs. 2C, S2B)7,8. Here, EGR1 is linked to epilepsy.