The rarity of SPINK2 variants and the fact that P2, the father of Br1 and Br2, also harboring a heterozygous mutation, presents in a milder phenotype than P105 could indicate that SPINK2 haploinsufficiency induces a milder phenotype of oligozoospermia with an incomplete penetrance on infertility. Here, CXCL11 is linked to Infertility.