In our work, we show that clinical parameters, such as menopausal status and histological factors such as hormone receptor expression, high grade of differentiation, high Ki67%-protein expression, the presence of lymphovascular or perineural invasion, and molecular alterations such as MMR deficiency are components of the sample of origin that significantly correlate with engraftment success during the PDX development process. Here, MRC1 is linked to hyperinsulinemic hypoglycemia, familial, 4.