Because apoptosis is a physiological phenomenon, the major function of apoptosis is to eliminate the unwanted cells from the body (15), the defects of apoptosis in the cell may result in or associate with a certain fraction of immune cell overpopulating in the body or/and in the local tissues, such as the apoptosis machinery is compromised in CD4+ T cells in allergic asthma patients (16). Here, CD4 is linked to allergic asthma.