Actb, also known as beta-actin, is a highly conserved cytoskeleton structural protein. It has long been regarded as a housekeeping gene. Actin proteins are essential components of the cytoskeleton, playing crucial roles in maintaining cell structure, cell motility, and intracellular transport. They are involved in pathways related to cell adhesion, such as focal adhesion, and the regulation of actin cytoskeleton dynamics [1,2].

Actb has been found to be closely associated with a variety of cancers. In most tumor cells and tissues, Actb is generally up-regulated. Its abnormal expression and polymerization, along with resulting cytoskeleton changes, are associated with cancer invasiveness and metastasis [1]. A pan-cancer analysis showed differential expression of Actb between cancer and adjacent normal tissues, and its expression was related to prognosis of tumor patients, immune cells infiltration, immune checkpoints, and other immune modulators in most cancers. Also, knockdown of Actb inhibited head and neck squamous carcinoma cell migration and invasion via NF-κB and Wnt/β-catenin pathways [2]. Moreover, in Becker's nevus, recurrent mutations (c.C439A or c.C439T) in Actb were detected in the majority of patients, and lesions above the waistline or covering more than 1% BSA were more likely to be positive for Actb mutations [3]. In congenital smooth muscle hamartomas (CSMHs), somatic missense Actb mutations were identified in 69% of cases, expanding the phenotypic spectrum of Actb mutations [4].

In conclusion, Actb is vital for maintaining normal cell structure and function through its role in the cytoskeleton. Studies, especially those using knockdown approaches in cancer cell lines, have revealed its significant impact on cancer-related processes such as invasion and metastasis, as well as its association with certain skin-related disorders like Becker's nevus and CSMHs. These findings contribute to our understanding of disease mechanisms and may potentially lead to new diagnostic and therapeutic strategies.