Quantum theory is by far our best description of the microscopic world. Surprisingly, there is nothing in the theory preventing macroscopic systems to be in quantum states. In principle, a cat could be dead and alive at the same time. A team of researchers around Nicolas Sangouard, in collaboration with colleagues from Innsbruck and Geneva, have written a review article presenting recent results on the difficulties and prospects of creating, maintaining, and detecting macroscopic quantum states. This review, which outlines the role of macroscopic quantum states in foundational questions as well as practical applications, has been published in the prestigious journal Reviews of Modern Physics and has been chosen for the cover of the next issue.