Provided are antisense poly-2'-O-(2,4-dinitrophenyl)oligoribonucleotides which are complementary to the IL-14.alpha. gene and/or transcribed IL-14.alpha. mRNA. Also provided are monoclonal antibodies reactive with discreet IL-14.alpha. peptides. The oligoribonucleotides and monoclonal antibodies are useful in inhibiting the growth of lymphocytes.