A vertical panel system comprises a vertical panel having a panel with opposing first and second panel surfaces and a base edge. Each micro- or nano-structure includes at least one portion made from the second semiconductor material, or each micro- or nano-structure having the first type of conductivity, a second end contacting the second semiconductor material to form the junction. Other aspects of the invention provide methods for treating a cancer that involve administering an agent that blocks storage of cholesteryl ester in a lipid droplet. The session state information detector may be configured to determine that the request does not include session state information.