Canellas. Referee Report. For: Pre-clinical Study: Immunohistochemical Evaluation of Matrix Metalloproteinase-13 on Rabbit (oryctolagus Cuniculus) Socket Healing After Application of Platelet-rich Fibrin with and Without Hydroxyapatite [version 2; Peer Review: 1 Approved, 1 Approved with Reservations]. F1000 Research Limited, 2022, doi:10.5256/f1000research.137236.r147248.