Here's what I found a while back when seeking info about tumor necrosis. 1) Necrosis in the tumor means that the cancer cells in that area are dead. The pathologic finding of necrosis suggests a fast-growing cancer. This often happens because the tumor runs out of blood supply in the central portion. Without a blood supply, the tumor cells cannot live.
Football cleats also come in the removable and molded variety. Molded cleats tend to be less expensive and are often required for youth play for safety reasons. Detachable football cleats are made of rubber, hard plastic or metal and come in a variety of lengths for use on different playing surfaces.
Metal spikes can be used by baseball players instead of plastic or rubber, but not for football cleats; although both can use shoes with plastic studs. This is due to the varying nature of baseball pitches, with some much harder to run on than others.