In this task, you are given an abstract of article. Your task is to generate title for this article. Preferred titles are under thirty words.

[EX Q]: T cell receptor (TCR-CD3) triggering involves both receptor clustering and conformational changes at the cytoplasmic tails of the CD3 subunits. The mechanism by which TCRalphabeta ligand binding confers conformational changes to CD3 is unknown. By using well-defined ligands, we showed that induction of the conformational change requires both multivalent engagement and the mobility restriction of the TCR-CD3 imposed by the plasma membrane. The conformational change is elicited by cooperative rearrangements of two TCR-CD3 complexes and does not require accompanying changes in the structure of the TCRalphabeta ectodomains. This conformational change at CD3 reverts upon ligand dissociation and is required for T cell activation. Thus, our permissive geometry model provides a molecular mechanism that rationalizes how the information of ligand binding to TCRalphabeta is transmitted to the CD3 subunits and to the intracellular signaling machinery.
[EX A]: Full activation of the T cell receptor requires both clustering and conformational changes at CD3.

[EX Q]: CONTEXT Venous thrombosis is a common complication in patients with cancer, leading to additional morbidity and compromising quality of life.
OBJECTIVE To identify individuals with cancer with an increased thrombotic risk, evaluating different tumor sites, the presence of distant metastases, and carrier status of prothrombotic mutations.
DESIGN, SETTING, AND PATIENTS A large population-based, case-control (Multiple Environmental and Genetic Assessment [MEGA] of risk factors for venous thrombosis) study of 3220 consecutive patients aged 18 to 70 years, with a first deep venous thrombosis of the leg or pulmonary embolism, between March 1, 1999, and May 31, 2002, at 6 anticoagulation clinics in the Netherlands, and separate 2131 control participants (partners of the patients) reported via a questionnaire on acquired risk factors for venous thrombosis. Three months after discontinuation of the anticoagulant therapy, all patients and controls were interviewed, a blood sample was taken, and DNA was isolated to ascertain the factor V Leiden and prothrombin 20210A mutations.
MAIN OUTCOME MEASURE Risk of venous thrombosis.
RESULTS The overall risk of venous thrombosis was increased 7-fold in patients with a malignancy (odds ratio [OR], 6.7; 95% confidence interval [CI], 5.2-8.6) vs persons without malignancy. Patients with hematological malignancies had the highest risk of venous thrombosis, adjusted for age and sex (adjusted OR, 28.0; 95% CI, 4.0-199.7), followed by lung cancer and gastrointestinal cancer. The risk of venous thrombosis was highest in the first few months after the diagnosis of malignancy (adjusted OR, 53.5; 95% CI, 8.6-334.3). Patients with cancer with distant metastases had a higher risk vs patients without distant metastases (adjusted OR, 19.8; 95% CI, 2.6-149.1). Carriers of the factor V Leiden mutation who also had cancer had a 12-fold increased risk vs individuals without cancer and factor V Leiden (adjusted OR, 12.1; 95% CI, 1.6-88.1). Similar results were indirectly calculated for the prothrombin 20210A mutation in patients with cancer.
CONCLUSIONS Patients with cancer have a highly increased risk of venous thrombosis especially in the first few months after diagnosis and in the presence of distant metastases. Carriers of the factor V Leiden and prothrombin 20210A mutations appear to have an even higher risk.
[EX A]: Malignancies, prothrombotic mutations, and the risk of venous thrombosis.

[EX Q]: BACKGROUND Most gynecologists determine therapy based on current International Society of Gynecologic Pathologists (ISGP)/World Health Organization classification of endometrial hyperplasia, the reproducibility of which has been questioned. The Gynecologic Oncology Group (GOG) initiated a protocol to assess the efficacy of hormonal therapy of atypical endometrial hyperplasia (AEH). Primary goals of the first phase (Part A) were to prospectively determine reproducibility of referring institution's pathologist's diagnosis of AEH by a panel of 3 gynecologic pathologists and to determine reproducibility of diagnoses by panel members.
METHODS Three hundred six women were entered on this protocol with a referring institution's pathologist diagnosis of AEH based on biopsy or curettage. Available slides were assessed independently and interpreted by each of a panel of 3 gynecologic pathologists who used International Society of Gynecologic Pathologists (ISGP)/World Health Organization criteria. The majority diagnosis was based on diagnostic concordance by at least 2 of the 3 panelists.
RESULTS The referring institution's pathologist's diagnosis of AEH was supported by the majority of the panel in only 38% of cases. Overall kappa value for the panel diagnosis of AEH was 0.28. The majority diagnosis was adenocarcinoma in 29%, cycling endometrium in 7%, and nonatypical hyperplasia in 18% of cases. Unanimous agreement for any diagnosis was reached among all 3 of the panel in 40% of cases. For the panel, paired kappa values for any diagnosis ranged 0.34-0.43, with an overall kappa value of 0.40.
CONCLUSION Reproducibility of referring institution's pathologists' diagnosis of AEH by a panel of gynecologic pathologists is poor. Both underestimation and overestimation of the severity of the lesion are very common. The level of reproducibility among subspecialist panel members for diagnosis of AEH in these specimens also is poor. Better criteria and better sampling are needed to improve reproducibility of this diagnosis, particularly if it is to be used for clinical decisions.
[EX A]:
Reproducibility of the diagnosis of atypical endometrial hyperplasia: a Gynecologic Oncology Group study.