Foster TH, Giesselman BR, Hu R, Kenney ME, Mitra S. Intratumor administration of the photosensitizer pc 4 affords photodynamic therapy efficacy and selectivity at short drug-light intervals. Transl Oncol. 2010 Apr;3(2):135–41. PMID: 20360938; PMCID: PMC2847321.