PVALB and allergic disease: This protein is often found in fast-twitch skeletal muscles and the nervous system and is often the cause of fish allergy [2]. It has been shown through molecular analysis that the alpha- and beta-isoforms of parvalbumin are the main proteins involved in fish and reptile allergy cross-reactivity given their similarity in protein structure, with beta-parvalbumin considered as the main immunoglobulin E-binding allergen [5].