The pCY‐pairs are sufficiently expressed as YFP‐SGGGDEVDGGGS‐CFP in cytoplasm, where activated caspase‐3 cleaves the ‐DEVD‐ and generates fluorescence of CFP and YFP through FRET “OFF” meaning of diagnosis “ON”, performing precise diagnosis of injury and progressive phases of PF. This evidence concerns the gene CFP and pemphigus foliaceus.