FERONIA (FER) was identified more than twenty years ago as a key regulator of female fertility in Arabidopsis thaliana (Arabidopsis). Along with 16 other closely related proteins, FER forms a distinct clade within the Arabidopsis superfamily of receptor-like kinases, having an extracellular domain for signal perception and a cytoplasmic domain that phosphorylates target molecules and induces cellular responses to incoming signals. In particular, FER is unique due to its multiple missions in controlling plant growth, immunity, and reproduction. There have been many recent (As of April 2024) advances in the FER regulation pathways, unveiling its positive and negative roles in immunity. This review aims to discuss how FER functions as a balance regulating key components in the FER pathway-peptides, proteins, reactive oxygen species, and hormones-and present a brief outlook for future research.