TP53 and hydatidiform mole: On the other hand, Halperin et al. evaluated the expression of the p53 and apoptosis in GTD and normal placenta and showed that the percentage of apoptotic cells demonstrated a significant increase in HMs compared with normal placenta and also significant overexpression of p53 in HMs compared with normal placenta, they concluded that p53 overexpression in hydatidiform moles could be the result of upregulation of apoptosis (31).