Although p53 mutant glioblastoma cell lines (SNB19, LN18, and T98G) did not respond effectively to photofrin based PDT, all p53 wild-type glioblastoma cell lines (A172, U87MG, and U118MG) displayed almost similar growth inhibition and decrease in cell viability after PDT with photofrin doses ranging from 0 to 60 μg/ml (Fig. 1c). The gene discussed is TP53; the disease is glioblastoma.