Water is a critical component of all living cells. Interestingly, tissue membranes show a great degree of water permeability. Mammalian red cells, renal proximal tubules, and descending thin limb of Henle are extraordinarily permeable to water. Water crosses hydrophobic plasma membranes either by simple diffusion or...

The INK4a-ARF locus is comprised of two tumor suppressors, p16INK4a and p14ARF. These two proteins are encoded through differential splicing of alternative first exons. The p16INK4a (exon 1alpha) protein inhibits the cyclin D-dependent kinases (CDK) that control the phosphorylation of the Rb protein and cell...