Investigation of the alkyl derivative of TMPyP4 (TMpyP4-C14), led to the observation that TMpyP4-C14 could efficiently enter cells and preferentially localize into the cytoplasm with binding to G4 structures in the 5′UTR of KRAS mRNA, resulting in 90% down regulation of KRAS protein expression in pancreatic cancer cells (Xodo et al., 2008). The gene discussed is KRAS; the disease is familial pancreatic carcinoma.