Human parainfluenza viruses, which belong to the paramyxovirus family, are pleomorphic viruses whose envelope is derived from the last host cell they infected. They comprise a group of four distinct serotypes of single-stranded RNA viruses. Human parainfluenza virus type 1 is the most common cause of croup and other upper and lower respiratory tract illnesses. Human parainfluenza virus type 2 infections usually follow type 1 infections and also cause croup and other upper and lower respiratory tract illnesses, and may cause aseptic meningitis and parotitis. Human parainfluenza virus type 2 forms filamentous particles in virus-infected, polarized epithelial cells. Human parainfluenza virus type 3 infections are associated with pneumonia as well as bronchiolitis and typically last longer than type 1 and 2 infections. Human parainfluenza virus type 4, one of the rubulaviruses, has a V protein with a highly conserved cysteine-rich domain characteristic of paramyxovirus V proteins. It is th

p16/INK4a [2D9A12]

p16/INK4A is a tumor-suppressor protein and that genetic and epigenetic abnormalities in genes controlling the G1 checkpoint can lead to both escape from senescence and cancer formation. The interaction of p16/INK4 family members can be a binary complex with CDK4/6 or ternary complex with cyclin D-bound CDK4/6 and ultimately results in the inhibition of cell cycle progression. As such, expression of p16 INK4A is commonly associated with cellular senescence, and disruption of the p16 INK4A gene is frequently observed in human tumor. The p16/INK4A locus is deleted in a wide spectrum of tumors including melanoma, pancreatic adenocarcinoma, glioblastoma, certain leukemias, non-small cell lung cancer, cervical cancer, and bladder carcinoma.

p16/INK4a [2D9A12]