In one aspect, a method is provided of inhibiting proliferation of a mammalian cell comprising introducing into said cell an effective amount of at least one at least one small interfering RNA agent (iRNA), wherein said iRNA comprises a nucleotide sequence of at least 15 nucleotides, wherein the nucleotide sequence comprises a seed region consisting of nucleotide positions 1 to 12, wherein position 1 represents the 5' end of the iRNA nucleotide sequence and wherein said seed region comprises a nucleotide sequence of at least six contiguous nucleotides that is complementary to six contiguous nucleotides within positions 1 to 12 of a nucleotide sequence, wherein position 1 represents the 5' end of the nucleotide sequence, wherein the nucleotide sequence is selected from the group consisting of SEQ ID NO: 1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:7 and SEQ ID NO:8. In some embodiments, the method comprises introducing at least one iRNA that inhibits the expression of at least one miR-16 responsive gene selected from TABLE 5 into the mammalian cell.