Custer Semen, South African Woman Runner

There are some diseases that primarily affect women, such as lupus. Also, there are some sex-related illnesses that are found more frequently or exclusively in women, e.g., breast cancer, cervical cancer, or ovarian cancer. Women and men may have different symptoms of an illness and may also respond differently to medical treatment. This area of medical research is studied by gender-based medicine.
During early fetal development, embryos of both sexes appear gender-neutral; the release of hormones is what changes physical appearance male or female. As in cases without two sexes, such as species that reproduce asexually, the gender-neutral appearance is closer to female than to male.