• Diagnosis of CD7 expressing (\> 98% CD7 expression on blast cells) T-ALL or LL and one of the following:

‣ Patients in 1st or subsequent relapse, after at least one standard frontline chemotherapy with BM involvement (MRD \>1% in 2 consecutive determinations or evidence of morphological relapse, i.e. \>5% blasts in BM);

⁃ Relapse after allogeneic HSCT, if at least 100 days post-transplant, if there is no evidence of active GVHD and if the patient is no longer taking immunosuppressive agents for at least 30 days prior to enrollment;

⁃ CNS disease as defined as \> 5 WBCs/mcL in CSF with morphological/flow-cytometry evidence of blasts or biopsy proven recurrence in the eye or brain;

⁃ Extramedullary relapse as defined by morphological evidence of blasts in the testis or any other extramedullary sites;

⁃ Refractory disease, defined as MRD ≥ 1% or \<1% but persistently positive (i.e. a positive MRD value confirmed by PCR at 2 subsequent evaluations performed at least 2 weeks apart), at the end of consolidation blocks in newly diagnosed patients;

• Age: 6 months - 25 years.

• Adequate venous access for apheresis or eligible for appropriate catheter placement, and no other contraindications for leukapheresis.

• Voluntary informed consent is given. For subjects \<18-year-old, or below the age required by each Country regulation, their legal guardian must give informed consent. Pediatric subjects will be included in age-appropriate discussion and verbal assent will be obtained for those greater than or equal to 12 years of age, when appropriate, or to sign age-adapted informed consent, according to the regulatory requirement of each Country.

• Clinical performance status: Patients \> 16 years of age: Karnofsky greater than or equal to 60%; Patients \< 16 years of age: Lansky scale greater than or equal to 60%.

• Diagnosis of CD7 expressing (\> 98% CD7 expression on blast cells) T-ALL or LL and one of the following:

‣ Patients in 1st or subsequent relapse, after at least one standard frontline chemotherapy with BM involvement (MRD \>1% in 2 consecutive determinations or evidence of morphological relapse, i.e. \>5% blasts in BM)

⁃ Relapse after allogeneic HSCT, if at least 100 days post-transplant, if there is no evidence of active GVHD and if the patient is no longer taking immunosuppressive agents for at least 30 days prior to enrollment

⁃ CNS disease as defined as \> 5 WBCs/mcL in CSF with morphological or flow-cytometry evidence of blasts or biopsy proven recurrence in the eye or brain

⁃ Extramedullary relapse as defined by morphological evidence of blasts in the testis or any other extramedullary sites

⁃ Refractory disease, defined as MRD ≥1% or \<1% but persistently positive (i.e. a positive MRD value confirmed by PCR at 2 subsequent evaluations performed at least 2 weeks apart), at the end of consolidation blocks in newly diagnosed patients

• Measurable or evaluable disease at the time of enrollment, which may include any evidence of disease, including MRD detected by flow-cytometry, cytogenetics, or polymerase chain reaction (PCR) analysis.

• Age: 6 months - 25 years.

• Before enrollment for treatment, patients must have a potential allogeneic hematopoietic stem cell (HSC) donor (matched related, matched unrelated or haploidentical) available.

• Voluntary informed consent is given. For subjects \<18-year-old, or below the age required according to each Country regulation, their legal guardian must give informed consent. Pediatric subjects will be included in age-appropriate discussion and verbal assent will be obtained for those greater than or equal to 12 years of age, when appropriate, or to sign age-adapted informed consent, according to the regulatory requirement of the Country.

• Clinical performance status: Patients \> 16 years of age: Karnofsky greater than or equal to 60%; Patients \< 16 years of age: Lansky scale greater than or equal to 60%.