JAK2 and breast cancer: Although JAK2 mutations are absent in the majority of solid tumors (Lee et al., 2006; Zhao and Moch, 2008; Herreros-Villanueva et al., 2010), mounting evidences suggest that aberrant JAK2 signaling has an essential role in solid tumors such as colorectal cancer, breast cancer, lung cancer, prostate cancer, etc., (Harry et al., 2012; Zhang et al., 2018).