Fig 1: JAB0505 is an ACVR1-blocking mAb.(A) Mouse C2C12 myoblast cells express similar levels of Acvr1 and Alk3, low levels of Alk1, and no detectable Alk6, as quantified by RT-qPCR (n = 3). ?CT values were calculated using the average CT values of the internal controls, Gapdh or Actb (ß-actin) (see Methods). Error bars represent ±SD. CT values >40 were considered not detected (N.D.). (B) Surface expression of ACVR1 and ALK3 on C2C12 cells, as detected by flow cytometry. (C) mAb JAB0505 binds to parental C2C12 cells, but not Acvr1-KO cells, as assessed by flow cytometry. (D) JAB0505 inhibits BMP9-induced signal activation in wild-type and ACVR1(R206H)-overexpressing C2C12 cells in a dose-dependent manner, as determined by quantification of BRE-luciferase activity (n = 3). Error bars represent ±SD.