B-cell lymphocytic leukaemia (B-CLL) is an indolent non-Hodgkin's lymphoma and the most frequent leukaemia. However, after many years, the incurable disease CLL has again become an exciting subject for research. Recently, both serum and molecular markers have been identified which could be used to predict the outcome of patients in early stages. With the advent of microarray analysis, novel diagnostic and therapeutic targets have been discovered. Here we describe the molecular strategies for target identification and validation. An evaluation of some established, and the most promising novel factors, with their diagnostic and prognostic applications is given. Potential therapeutic target molecules and their inhibitors are reviewed.