According to recent findings by the Matzuk group, in which the Cre-loxP approach was applied for the generation of mice with conditional knock-out of ALK5 or Smad2/3 in the uterus, the TGFβ pathway appeared to be a key player not only in the uterine physiology but also as an essential factor contributing to the cancer development of this organ. The gene discussed is TGFB1; the disease is cancer.