High RARA expression is a biomarker predicting sensitivity for rhIGFBP7-induced ATRA susceptibility in primary AML. Gene expression levels for GFI1 and RARA were measured by qRT-PCR (in triplicate). Patient sample characteristics of responders and nonresponders to rhIGFBP7 and ATRA combination treatment are summarized in supplemental Table 1. (A) Log2-transformed GFI1 gene expression in EVI-1⁻ (n = 50) and EVI-1⁺ (n = 10) AML samples at diagnosis, measured relative to GUS expression. The relative GFI1 expression of 1 of the EVI-1⁺ AML samples was set at 1. IGFBP7 (B), GFI1 (C), and RARA (D) expression in responders and nonresponders to rhIGFBP7 and ATRA combination treatment, relative to HMBS expression, as measured by qRT-PCR. (E) GFI1 and RARA gene expression levels in responders and nonresponders to the combination of rhIGFBP7 and ATRA, relative to HMBS, as by qRT-PCR. Spearman’s correlation coefficients were calculated. *P < .05, **P < .01, Student t test, unless stated otherwise.