Schematic representation of genomic deletion constructs used to define the IFN responsive region in the 3.2-kb 5′ flanking sequence of the Ly-6E gene. The map shows the intact gene coding for the Ly-6A antigen that was present in all these constructs. The region between the two PstI sites is the PstI fragment used for further subcloning. Restriction sites in the map are abbreviated as follows: H, HindIII; S, SpeI; Ap,ApaI; Ps, PstI; Bs, BstEII; K, KpnI; Av,AvaI; R, EcoRI.