The present invention relates to methods and kits for detecting several polynucleotide sequence found to be indicative of a poor prognosis of B-CLL. All the polynucleotides are transcribed from a region on human chromosome 12p21-22. Most of the polynucleotides do not encode larger polypeptides, but may encode small peptides, they may function as RNAs. Four polynucleotides encode a novel protein, which in one preferred embodiment can be used as a cytokine, preferably as an interleulkin. Furthermore the invention relates to methods and compositions for treating B-CLL in particular poor prognosis B-CLL.
