BCR and allergic rhinitis: In a prospective observational birth cohort study, Phl p 1 was identified as an initiator of IgE sensitization in >75% of children with grass pollen-related seasonal allergic rhinitis, followed by antibody production in response to seven other allergic molecules (i.e., Phl p 2, Phl p 4, Phl p 5, Phl p 6, Phl p7, Phl p 11, and Phl p 12) of P. pratense [14].