Supporting this observation, these cancer cells expressed lower levels of mRNA for the mitochondrial iron transporters, mitoferrin-1 and mitoferrin-2.30 Silencing both transporters in healthy mouse fibroblasts (NIH 3T3) increased PpIX levels compared with controls.49 Whether the expression of the mitoferrin transporters is dysregulated in cancer is not clear. The gene discussed is SLC25A28; the disease is cancer.