单项选择题
Which one is correct about tumor suppressor genes? ()
A．Has the effect of inhibiting cell proliferation
B．Normally expressed in all tumor cells
C．Does not affect cell proliferation and differentiation after deletion
D．Not present in normal human cells
E．Not related to oncogene expression
Which one is correct about tumor suppressor genes? ()
A．Has the effect of inhibiting cell proliferation
B．Normally expressed in all tumor cells
C．Does not affect cell proliferation and differentiation after deletion
D．Not present in normal human cells
E．Not related to oncogene expression
（ ）