(joint with Pawel Hitczenko). Tree-like tableaux are combinatorial objects which exhibit a natural tree structure and are connected to the partially asymmetric simple exclusion process (PASEP). There was a conjecture made on the total number of corners in tree-like tableaux and the total number of corners in symmetric tree-like tableaux. I will discuss the proof of both of these conjectures. The proofs are based on bijections with permutation tableaux and type-B permutation tableaux and consequently, results for these tableaux will also be discussed.