Sometimes even cells get tired. When the T cells of your immune system are forced to deal over time with cancer or a chronic infection such as HIV or hepatitis C, they can develop "T cell exhaustion," becoming less effective and losing their ability to attack and destroy the invaders of the body.

HDL is the “good cholesterol” that helps remove fat from artery walls, reversing the process that leads to heart disease. Yet recent drug trials and genetic studies suggest that simply pushing HDL levels higher doesn’t necessarily reduce the risk of heart disease. Now, a team led by scientists from the Perelman School of Medicine at the University of Pennsylvania has shown in a large, forward-looking epidemiological study that a person’s HDL function—the efficiency of HDL molecules at removing cholesterol—may be a better measure of coronary heart disease risk and a better target for heart-protecting drugs.

An important link between the human body clock and the immune system has relevance for better understanding inflammatory and infectious diseases, discovered collaborators at the Perelman School of Medicine at the University of Pennsylvania and Trinity College, Dublin.

Cell division is the basis of life and requires that each daughter cell receive the proper complement of chromosomes. In most organisms, this process is mediated at the familiar constricted intersection of X-shaped chromosomes. This area, called the centromere, is where special proteins gather and attach to pull daughter cells apart during cell division.

A study in this week’s Science Translational Medicine is a classic example of how seemingly unlikely collaborators can come together to make surprising discoveries.

The National Institutes of Environmental Health Sciences (NIEHS), part of the National Institutes of Health (NIH), has renewed its funding to the Center of Excellence in Environmental Toxicology (CEET), at the University of Pennsylvania’s Perelman School of Medicine, for the next five years.

President Barack Obama launched the "Precision Medicine Initiative” this past winter during the State of the Union address, and politicians on both sides of the aisle applauded the announcement. Broadly, precision medicine is meant to help diagnose individuals more accurately and better tailor treatment according to their physiology.

Two researchers from the Perelman School of Medicine at the University of Pennsylvania have been elected as new members to the American Academy of Arts and Sciences, one of the nation's most prestigious honorary societies and a leading center for independent policy research.

RNA is both the bridge between DNA and the production of proteins that carry out the functions of life and what guides which and how much protein gets made.

Understanding the molecular signals that guide early cells in the embryo to develop into different types of organs provides insight into how tissues regenerate and repair themselves.