In this talk I will discuss 2 subjects related to the existence or not of de Sitter vacua in string theory. First, I will describe the general tension between results based on 4D supergravity and those coming from a higher dimensional perspective. This will include a 10D analysis of a particular 4D proposal. Then I will switch to a recent conjecture which claims that such vacua don't exist in string theory and study its possible consequences for inflation.