Statement of Retraction. Iria Nieto-Vázquez, Sonia Fernández-Veledo, Cristina de Alvaro, Cristina M. Rondinone, Angela M. Valverde, and Margarita Lorenzo. Protein–Tyrosine Phosphatase 1B–Deficient Myocytes Show Increased Insulin Sensitivity and Protection Against Tumor Necrosis Factor-α–Induced Insulin Resistance. Diabetes 2007;56:404–413. https://doi.org/10.2337/db06-0989

After learning that certain representative immunoblot images in the above-cited paper may have been duplicated, authors Iria Nieto-Vázquez, Sonia Fernández-Veledo, Cristina M. Rondinone, and Ángela M. Valverde have decided to voluntarily retract the article. The potential duplications occur in the following images:

• The GLUT1 strip of Fig. 1, lanes 1 and 2

• The α-Actin strip in Fig. 1 and lanes 4–7 of the β-Actin strip in Fig. 7E, as well as the full β-Actin strip in Fig. 7E and the αACTIN strip in Fig. 3E in a later published 2008 paper:

   Iria Nieto-Vazquez, Sonia Fernández-Veledo, Cristina de Alvaro, Margarita Lorenzo. Dual role of interleukin-6 in regulating insulin sensitivity in murine skeletal muscle. Diabetes 2008;57:3211–3221. https://doi.org/10.2337/db07-1062

• Fig. 2B, lane 3 of IP:IRS-1/WB:P-Tyr and lane 5 of IP:IRS-1/WB:IRS-1, as well as lane 4 of IP:IRS-1/WB:P-Tyr and lane 2 of IP:IRS-1/WB:IRS-1

• The WB:P-Tyr strip of Fig. 3A, lanes 1 and 6 and lanes 4 and 8

• Fig. 4A, the bottom origin spots in lanes 4 and 10

• Lanes 1–3 of the AKT strip in Fig. 5A and lanes 1–3 of the p70S6K strip in Fig. 5B, as well as lanes 9 and 10 of the AKT strip in Fig. 5A and lanes 4 and 5 of the p70S6K strip in Fig. 5B

• Fig. 7D, lanes 3 and 8 of the P-AKT Ser 473 strip

• Fig. 7E, lanes 3 and 7 and lanes 5 and 8 of the SH-PTP2 strip

• The β-Actin strip of Fig. 8C, lanes 1–3 of the left panel and lanes 2–4 of the right panel, as well as lane 8 of the left panel and lane 5 of the right panel

• Fig. 8E, lanes 2 and 4 of the left panel of P-AKT Ser 473, as well as lanes 7 and 8 of the right panel

Because the laboratory of the senior author, the late Dr. Margarita Lorenzo, was dismantled and closed immediately after her death in 2010, many of the original source files could not be found; therefore, it is not possible to fully assess the above-cited anomalies. As such, Drs. Nieto-Vázquez, Fernández-Veledo, Rondinone, and Valverde have decided that the best course of action is to retract this article. Dr. de Alvaro could not be reached to provide her input. The submitting authors of this statement regret this situation and apologize to the scientific community for any inconvenience this may have caused.

• © 2020 by the American Diabetes Association