IGF1 and acute lymphoblastic leukemia: Of note, we previously reported that patient-derived xenograft T-ALL cells carrying homozygous PTEN frameshift mutations and cultured ex vivo in defined media with supplemental IL-7 were sensitive to IGF1R inhibition with CP-751,871[53], further supporting our conclusions that IGF-1 and IL-7 are non-redundant and that PTEN loss in itself does not confer IGF independence.