 The Phase 1 portion of the study evaluated the pharmacokinetic profile and safety of ABT-263 with the objective of defining the dose limiting toxicity and maximum tolerated dose in subjects with lymphoid malignancies. The Phase 2a portion of the study is evaluating ABT-263 using a step-up dosing regimen and may be increased to the defined recommended Phase 2 dose to obtain additional safety information and a preliminary assessment of efficacy in subject with lymphoid malignancies. The Extension portion of the study is to allow Phase 2a subjects who remain active 1 year after the last subject enrolls or who have been on study approximately 1 year to continue receiving ABT-263 with less frequent study evaluations. Subjects in the Extension Study will continue receiving study drug for up to 7 years after the last subject transitions to the Extension Study, or until disease progression or toxicity that necessitates discontinuation whichever comes first. 