SMO and chronic myelogenous leukemia, BCR-ABL1 positive: Beta-arrestins, a family of ubiquitous cellular scaffold proteins, are important signaling adaptors, facilitating activation of various pathways77, 78 that are closely correlated to cellular proliferation, differentiation, or apoptosis79 and several tumorigenic events.80, 81 It was demonstrated that β-arrestin 2, a member of the β-arrestin family, was critical in the initiation and progression of CML via modulation of the Hh/Smo and Wnt/Fz pathways; this indicates that β-arrestin 2 is a viable target in treating CML.82