The Kell (ISBT #006) blood group system currently consists of 36 antigens and more than 100 alleles, about half of which encode for a Kell null (K SB 0 sb ) phenotype, nearly always on a I KEL*02 i background.1 Nevertheless, the K SB 0 sb phenotype is rare, with most individuals identified after they have made anti-Ku (anti-KEL5). BRIEF SUMMARY We report five novel silenced I KEL i *02 alleles detected in two donors with a k phenotype/genotype discrepancy and in three patients who made anti-Ku. [Extracted from the article]