Before revision:  To the best of our knowledge, this is the first mathematical study to support the validity of the T-helper/ T-regulator lymphocyte ratio as an index of immunosuppression , with a potential for prognostic monitoring .
After revision:  To the best of our knowledge, this is the first mathematical study to support the validity of the T-helper/ T-regulator lymphocyte ratio as an index of immunosuppression and may provide a useful theoretical benchmark to interpret and compare experiments .