This is an announcement for the paper "Existence and uniqueness of greedy bases in Banach spaces" by J. L. Ansorena, F. Albiac, S. J. Dilworth and Denka Kutzarova. Abstract: Our aim is to investigate the properties of existence and uniqueness of greedy bases in Banach spaces. We show the non-existence of greedy basis in some Nakano spaces and Orlicz sequence spaces and produce the first-known examples of non-trivial spaces (i.e., different from $c_0$, $\ell_1$, and $\ell_2$) with a unique greedy basis. Archive classification: math.FA Mathematics Subject Classification: 46B15 (Primary) 46B45 (Secondary) Submitted from: joseluis.ansorena@unirioja.es The paper may be downloaded from the archive by web browser from URL http://front.math.ucdavis.edu/1505.08119 or http://arXiv.org/abs/1505.08119