Presence of the CIII protein in the cell results in the stabilization of the CII transcriptional activator (a very unstable protein), CII activates CI, the gene for repressor, and thus promotes the establishment of lysogeny. C3 MIIAIAGSARMGVSQLHESLLDRITRKLRAGWKRLADILNQPGVPSHDYCAC Regulatory protein C3 RPC3_BPP22 CIII 52