Compared with the genome of nongestational malignant PTs, our genome sequencing results revealed that the analyzed tumors shared some common alterations with nongestational malignant PTs, including ATM, TP53, RB1, and PTEN. Additionally, some genes were detected for the first time in malignant PTs during pregnancy and lactation, but their significance in tumor formation and progression is unknown. This evidence concerns the gene RB1 and neoplasm.