TGFB1 and cervical cancer: For cervical cancers without HPV infection, we have constructed the following regression model:(10)ypx=17.56∗f1x−1.36∗10−3∗f2x−1.6∗10−2∗f1x∗f2x+1.34where f1x is the age-dependent distribution of the cancer risk, and f2x is the age-dependent distribution of blood level of TGFβ1, identified to be the sole growth signal specifically needed for this class of cervical cancer.