PROS1 and hypereosinophilic syndrome: Zittoun Zittoun J J Farcet Farcet JP JP Marquet Marquet J J Sultan Sultan C C Zittoun Zittoun R R Cobalamin (vitamin B12) and B12 binding proteins in hypereosinophilic syndromes and secondary eosinophilia Cobalamin (vitamin B12) and B12 binding proteins in hypereosinophilic syndromes and secondary eosinophilia Blood Blood 1984 1984 63 63 779 779 83 83 6704540 6704540