Surprisingly, recent work by Michael J. Welsh’s group (University of Iowa) also showed, through multivariate analysis based on a very large series of obligatory heterozygous subjects (parents of an affected child), that pancreatitis and male infertility occurred significantly more often in patients carrying CFTR mutations, although these individuals are considered asymptomatic a priori [87]. The gene discussed is CFTR; the disease is male infertility.