When a proto-oncogene is transformed into a cancer-causing gene by some factor,it is called .......?

Retroviruses are involved in cancer in humans because they ...............

Oncogene is another name for

Which of the following statements are correct?
$A.$ Computed tomography and magnetic resonance imaging detect cancers of internal organs.
$B.$ Chemotherapeutic drugs are used to kill non-cancerous cells.
$C.$ $\alpha$-interferon activates the cancer patients' immune system and helps in destroying the tumour.
$D.$ Chemotherapeutic drugs are biological response modifiers.
$E.$ In the case of leukaemia,blood cell counts are decreased.
Choose the correct answer from the options given below:

Cancer cells are characterized by:

Cancer of the internal organs is detected by