SMAD4 and infectious disease: While this canonical role of SMAD4 is well-established, emerging evidence suggests that SMAD4 also exhibits TGF-β-independent functions in diverse biological contexts, such as cancer (Mo et al., 2022), infectious diseases (Gowripalan et al., 2020), and immune responses (Wang et al., 2018b; Igalouzene et al., 2022; Chandiran and Cauley, 2023).