Decreased alpha2beta1 in 4 strains carrying Itga 2 haplotype 2 results from decreased affinity of heterogeneous ribonucleoprotein L ( hnRNP L ) for a 6 CA repeat sequence ( CA 6 ) within intron 1 . ^^^ By UV crosslinking and immunoprecipitation , hnRNP L binds more avidly to CA 21 , relative to CA 6 . ^^^