We have found that [24], among the familial VTE patients, pore forming protein gene mutations located in NK cells, T cells and complements, were detected in 3 patients with the results of a combined cell deficiency of killing targeted cells. NK cells, CD ₈ T cells and complements form the membrane attack complex. The steps of killing foreign or pathological antigen cells include membrane perforation and release of the granzyme.The mutation of pore forming protein gene can lead to membrane perforation function loss. The genomics of symptomatic PE patients showed the significant downregulation of T cell granzyme mRNA expression, which indicates the decreased function of killing cells. Both the mutation and downregulated granzyme mRNA expression suggest the decreased killing activities of immune cells.