An isolated polynucleotide at leat 60 % homologous to SEQ ID NO: 1, 3, 5 or 18encoding a SARP polypeptide; vectors comprising a polynucleotide sequenceencoding at least 11 consecutive amino acids of .alpha.SARP polypeptide; ahost cell transformed with an isolated polynucleotide or vector; antibodiesspecific for SARP and use of such polynucleotides and antibodies in diagnosticand therapeutic method. Therapeutic uses of antibodies and polynucleotides ofsarp. Methods for treating diseases related to the regulation of SARPexpression in tissue and bodily fluid samples, including cancers.