Targeted deletion in testicular germ cells of the gene encoding the catalytic subunit of PP2A (isoform α, PPP2CA) or the gene encoding the catalytic subunit of PP1 (isoform γ, PPP1CC) leads to spermatogenesis defects and male infertility in both cases (11, 59, 60). The gene discussed is PTPA; the disease is male infertility.