  Stellar clusters are open windows to understand stellar evolution.
Specifically, the change with time and the dependence on mass of different
stellar properties. As such, they are our laboratories where different theories
can be tested. We try to understand the origin of the connection between
lithium depletion in F, G and K stars, rotation and activity, in particular in
the Pleiades open cluster. We have collected all the relevant data in the
literature, including information regarding rotation period, binarity and
activity, and cross-matched with proper motions, multi-wavelength photometry
and membership probability from the DANCe database. In order to avoid biases,
only Pleiades single members with probabilities larger than p=0.75 have been
included in the discussion. Results. The analysis confirms that there is a
strong link between activity, rotation and the lithium equivalent width excess,
specially for the range Lum(bol) = 0.5-0.2 Lsun (about K2-K7 spectral types or
0.75-0.95 Msun). It is not possible to disentangle these effects but we cannot
exclude that the observed lithium overabundance is partially an observational
effect due to enhanced activity, due to a large coverage by stellar spots
induced by high rotation rates. Since a bona fide lithium enhancement is
present in young, fast rotators, both activity and rotation should play a role
in the lithium problem.
