The Kiwellin protein family represents a fascinating example of molecular versatility, spanning roles in both human allergenicity and plant immune responses. Initially characterized as major allergens in kiwifruit, Kiwellins have since been identified across diverse plant species, where they play critical roles in defense against fungal and microbial pathogens. Recent structural and functional studies reveal a conserved protein fold with variable regions likely shaped by co-evolution with pathogens. This presentation will highlight the evolutionary trajectory of Kiwellins, their functional diversification, and emerging insights into their molecular mechanisms in plant-pathogen interactions.