A surgical stapler can comprise an anvil comprising a staple pocket formed in a tissue contacting surface. The staple pocket can comprise a longitudinal axis, a first forming cup, and a second forming cup. The first forming cup can comprise a first interior sidewall comprising a first vertical portion...http://www.google.se/patents/US8141762?utm_source=gb-gplus-sharePatent US8141762 - Surgical stapler comprising a staple pocket