SLC25A37 and cancer: 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.