A decade ago, the (pro)renin receptor ((P)RR) was discovered and depicted as a potential activator of the tissue renin-angiotensin system. For this reason, the role of the (P)RR in cardiovascular diseases and diabetes has been particularly studied. However, the discovery of embryonic lethality after (P)RR gene deletion in mouse and zebrafish paved the way for additional roles of (P)RR in cell homeostasis. Indeed, the (P)RR has been shown to associate with the vacuolar H + -ATPase, hence its other name ATP6ap2. Developmental studies in Xenopus and Drosophila have revealed an essential role of this association to promote the canonical and non-canonical Wnt signaling pathways, while studies with tissue specific gene deletion have pointed out a role in autophagy. This review aims to summarize recent findings on the cellular functions of (P)RR emerging from various mutated and transgenic animal models.