{HEAD ~ A recent study} examined {TAIL ~ the human p57KIP2} for genetic variations in a large number of tumors (Tokino et al., “Characterization of the human p57 gene: alternative splicing, insertion/deletion polymorphisms in VNTR sequences in the coding region, and mutational analysis.” 
examined
{ HEAD ~ A recent study } examined { TAIL ~ the human p57KIP2 } for genetic variations in a large number of tumors ( Tokino et al . , “ Characterization of the human p57 gene : alternative splicing , insertion / deletion polymorphisms in VNTR sequences in the coding region , and mutational analysis . ”
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