PTEN and familial pancreatic carcinoma: While we only analyzed the PTEN mRNA levels 12 and 24 h after incubation of PANC-1 cells with TGF-β1, we cannot exclude the possibility that a rapid reduction of PTEN mRNA levels had taken place earlier in the pancreatic cancer cells as well, which may have been followed by a restitution of PTEN mRNA levels and a second decrease 24 h after treatment of the cells.