In-vitro forced expression of sarcoplasmic reticulum Ca2+ ATPase (Serca2a) improved contractility function of CML cells that, in turn, was associated with downregulation of Pitx2 and Myf5 mRNA levels in Serca2a-transduced cells (see the data set available at NCBI through accession number GSE35108). This evidence concerns the gene PITX2 and chronic myelogenous leukemia, BCR-ABL1 positive.