Study of Hyperbaric Oxygen Therapy in Addition to Standard Growth Factor Support for Hematopoietic Progenitor/Stem Cell Mobilization

Inclusion Criteria: * Patients who are being considered for autologous stem cell transplant as part of their routine care who have failed at least one prior attempt at stem cell mobilization with any of currently available standard regimens using growth factors. * Patients in who the use of Mozobil® is medically justified but is not possible because of insurance or financial reasons * Patients scheduled to begin standard growth factor treatment with Neupogen® as part of routine care. * Patients who have had a bone marrow evaluation performed within one month prior to enrollment as part of routine clinical care or under IRB# 02815. * Patients who have had a chest x-ray or CT Chest within 60 days prior to enrollment. * ECOG performance status ≤ 3 performed within 60 days prior to enrollment which will be determined by history. * Patients who are at least 18 years of age at the time of registration. * Patient must have signed an IRB-approved informed consent and understand the investigational nature of the study. Exclusion Criteria: * Clinically significant hepatic dysfunction as noted by direct bilirubin or AST \>3 times the upper normal limit or clinically significant concurrent hepatitis within 60 days prior to enrollment. * History of New York Heart Association (NYHA) Class III or Class IV heart failure * Recent (\< 6 months) myocardial infarction, unstable angina, difficult to control congestive heart failure, uncontrolled hypertension, or difficult to control cardiac arrhythmias from medical history. * Untreated pneumothorax from medical history. * Uncontrolled seizure disorder from medical history * Uncontrolled insulin dependent diabetes (verified by routine labs in medical record) * History of severe claustrophobia * Severe COPD (FEV1 \< 50% of predicted on pulmonary function test) performed within 60 days prior to enrollment * Untreated ear barotraumas from medical history * Pregnancy or currently breastfeeding (females of childbearing potential must agree to use adequate contraception during the study). A urine pregnancy test will be performed prior to initiating HBOT. * Patients currently receiving Bleomycin, Cisplatin, Disulfiram, Doxorubicin, and Sulfamylon. * Any other condition that the PI determines may jeopardize the safety of the subject during the course of the study