Muscle stem cells (MuSCs) are key contributors to the repair of skeletal muscle. In response to acute or chronic injury, quiescent MuSCs differentiate into myoblasts (MBs), which further differentiate into mature myofibers. Treatments involving transplantation of MuSCs into damaged muscle tissue often have limited success due to decreased engraftment ability of in vitro cultured MuSCs. Understanding the signaling mechanisms governing MuSC proliferation and differentiation may lead to improved MuSC transplantation therapies. Within the MuSC niche, various cytokine signaling molecules play a vital role in regulating MuSC quiescence, differentiation and proliferation. Understanding how specific cytokine signaling molecules lead to a particular MB cell fate is critical for the development of effective in vitro MuSC expansion protocols that generate sufficient numbers of cells while maintaining functionality. In vitro culture of primary MBs and immunostaining techniques have provided an in-depth understanding of how particular components of the MuSC signaling network influence MuSC and MB phenotype.