CA9 and neoplasm: In the current study, the apoptotic effect of TMPyP4-PDT on tumor cells and the expression levels of minichromosome maintenance protein-2 (MCM2) and carbonic anhydrase (CA)-IX were investigated by analyzing the apoptotic rate of the human ovarian carcinoma A2780 cell line in vitro in order to highlight the clinical significance of TMPyP4-PDT in the treatment of ovarian carcinoma patients.