  We compare three different setups for measuring cell-cell adhesion. We show
that the measured strength depends on the type of setup that is used. For
identical cells different assays measure different detachment forces. This can
be understood from the fact that cell-cell detachment is a global property of
the system. We also analyse the role of external force and line tension on
contact angle and cell-cell detachment. Comparison with experiment suggests
that the current data are essentially dynamical in nature. We dedicate this
article to Fyl Pincus who for many of us is an example to be followed not only
for outstanding science but also for a marvelous human behavior.
