Evaluation of SHP-1 mRNA expression level in BM samples and CD34⁺ primary cells derived from patients with CP-CML. (A) SHP1 expression level assessed by RT-qPCR in BM of 60 patients with CP-CML at baseline. Patients are classified, according to the ENL definitions in optimal, suboptimal, and failure responder, and SHP-1 expression is compared with that assessed in 21 untreated patients with MPN. Straight lines indicate mean values of the 4 groups of subjects. Statistical analysis is performed by nonparametric Mann-Whitney test showing a significant difference in SHP1 expression in optimal responders compared with suboptimal (P = .002) or failure responders (P < .0001). No statistical difference is observed in SHP-1 expression between patients with MPNs and optimal responders. (B) SHP-1 expression level is analyzed in CD34⁺ progenitor cells derived from BM samples of 6 optimal responders, 6 failure responders, 3 patients with MPN, and 3 HDs. Graphs show minimum and maximum values of the normalized SHP-1 mRNA copy number; straight lines indicate mean values of the 4 groups of subjects. Statistical analysis is performed by nonparametric Mann-Whitney test showing a significant difference in SHP1 expression in CD34⁺ cells derived from optimal responders compared with failure responders (P = .008). No statistical difference is observed in SHP-1 expression between CD34⁺ cells derived from HDs, patients with MPNs, and optimal responders. (C) SHP-1 mRNA expression assessed by RT-qPCR in BM cells of 10 failure responders at diagnosis and after 18 months of IMA treatments. Each symbol represents SHP-1 mRNA expression in a single patient. Straight lines indicate mean values of the 2 groups of subjects. Statistical analysis is performed by nonparametric Mann-Whitney test showing a significant difference in SHP1 expression in failure patients at diagnosis and during follow-up (P = .002).