PALB2 and sexually transmitted disease: Such factors may include one or more of the following: the onset of sexual life before the age of 15; multiple sexual partners [9,10]; immunosuppressive conditions (e.g., HIV, long-term treatment with steroid hormones); cervical and vaginal microbiome alterations [11,12,13]; sexually transmitted infections (STIs) [14,15,16]; estrogen and progesterone imbalance, and sex-steroid hormone receptors malfunction [17,18,19,20]; genetic predisposition through polymorphism of HLA, MTHFR, PALB2, POLE3, as well as other possible genes and smoking [21,22,23].