To determine whether the peptide sequences displayed on PC5-2 would actually interact with NSCLC cells, we used fluorescein isothiocyanate (FITC)-labeled SP5-2 peptide (FITC-SP5-2) in place of the PC5-2 phage for a peptide-binding assay through immunofluorescent staining. Here, SP5 is linked to non-small cell lung carcinoma.