Patient description: The patient is a 16-year-old girl recently diagnosed with myasthenia gravis, class IIa. She complains of diplopia and weakness affecting in her upper extremities. She had a positive anti-AChR antibody test, and her single fiber electromyography (SFEMG) was positive. She is on acetylcholinesterase inhibitor treatment combined with immunosuppressants. But she still has some symptoms. She does not smoke or use illicit drugs. She is not sexually active, and her menses are regular. Her physical exam and lab studies are not remarkable for any other abnormalities. BP: 110/75 Hgb: 11 g/dl WBC: 8000 /mm3 Plt: 300000 /ml Creatinine: 0.5 mg/dl BUN: 10 mg/dl Beta hcg: negative for pregnancy

Clinical trial eligibility criteria: eligible ages (years): 1.0-21.0,  Advanced Malignant Solid Neoplasm Ann Arbor Stage III Non-Hodgkin Lymphoma Ann Arbor Stage IV Non-Hodgkin Lymphoma Malignant Glioma Recurrent Ependymoma Recurrent Ewing Sarcoma Recurrent Glioma Recurrent Hepatoblastoma Recurrent Langerhans Cell Histiocytosis Recurrent Malignant Germ Cell Tumor Recurrent Malignant Solid Neoplasm Recurrent Medulloblastoma Recurrent Neuroblastoma Recurrent Non-Hodgkin Lymphoma Recurrent Osteosarcoma Recurrent Peripheral Primitive Neuroectodermal Tumor Recurrent Primary Central Nervous System Neoplasm Recurrent Rhabdomyosarcoma Recurrent Soft Tissue Sarcoma Refractory Langerhans Cell Histiocytosis Refractory Malignant Germ Cell Tumor Refractory Malignant Solid Neoplasm Refractory Neuroblastoma Refractory Non-Hodgkin Lymphoma Refractory Primary Central Nervous System Neoplasm Rhabdoid Tumor Stage III Osteosarcoma AJCC v7 Stage III Soft Tissue Sarcoma AJCC v7 Stage IV Osteosarcoma AJCC v7 Stage IV Soft Tissue Sarcoma AJCC v7 Stage IVA Osteosarcoma AJCC v7 Stage IVB Osteosarcoma AJCC v7 Wilms Tumor Patient must have enrolled onto APEC1621SC and must have been given a treatment assignment to Molecular Analysis for Therapy Choice (MATCH) to APEC1621D based on the presence of an actionable mutation; note that treatment assignment may be to primary cohort A for patients with TSC1 or TSC2 loss of function mutations, primary cohort B for patients with other PI3K/MTOR pathway mutations, a histology specific biomarker positive expansion cohort if the to open such a cohort are met, or a biomarker negative expansion cohort if the to open such a cohort are met Patients accruing to dose level 1 must have a body surface area >= 0.52 m^2 at the time of study enrollment; patients accruing to dose level 2 must have a body surface area >= 0.37 m^2 at the time of study enrollment; patients accruing to dose level -1 must have a body surface area >= 0.75 m^2 at the time of study enrollment Patients must have radiographically measurable disease at the time of study enrollment; patients with neuroblastoma who do not have measurable disease but have metaiodobenzylguanidine (MIBG) positive (+) evaluable disease are eligible; measurable disease in patients with CNS involvement is defined as tumor that is measurable in two perpendicular diameters on magnetic resonance imaging (MRI) and visible on more than one slice Note: The following do not qualify as measurable disease Malignant fluid collections (e.g., ascites, pleural effusions) Bone marrow infiltration except that detected by MIBG scan for neuroblastoma Lesions only detected by nuclear medicine studies (e.g., bone, gallium or positron emission tomography [PET] scans) except as noted for neuroblastoma Elevated tumor markers in plasma or cerebrospinal fluid (CSF) Previously radiated lesions that have not demonstrated clear progression post radiation Leptomeningeal lesions that do not meet the measurement requirements for Response Evaluation in Solid Tumors (RECIST) 1.1  Pregnant or breast-feeding women will not be entered on this study; pregnancy tests must be obtained in girls who are post-menarchal; males or females of reproductive potential may not participate unless they have agreed to use an effective contraceptive method while receiving study treatment and for 3 months after the last dose of LY3023414 Concomitant medications Corticosteroids: patients receiving corticosteroids who have not been on a stable or decreasing dose of corticosteroid for at least 7 days prior to enrollment are not eligible; if used to modify immune adverse events related to prior therapy, >= 14 days must have elapsed since last dose of corticosteroid Investigational drugs: patients who are currently receiving another investigational drug are not eligible Anti-cancer agents: patients who are currently receiving other anti-cancer agents are not eligible Anti-GVHD agents post-transplant: patients who are receiving cyclosporine, tacrolimus or other agents to prevent graft-versus-host disease post bone marrow transplant are not eligible for this trial Patients who have an uncontrolled infection are not eligible Patients who have insulin dependent diabetes are not eligible Patients who have received a prior solid organ transplantation are not eligible Patients with subependymal giant cell astrocytomas (SEGAs) are not eligible