RhoA, short for Ras homolog gene family member A, is a small GTPase of the Rho family. It is crucial in regulating multiple signal transduction pathways, influencing diverse cellular functions such as cell survival, migration, adhesion, proliferation, and cytoskeletal dynamics [1,2]. The RhoA/ROCK signaling pathway, with Rho-associated coiled-coil kinase (ROCK) being a downstream serine/threonine kinase, is involved in processes like cell migration, proliferation, and survival [3].

RhoA has been implicated in numerous diseases. In neurodegenerative diseases such as Parkinson's, Alzheimer's, Huntington's, and amyotrophic lateral sclerosis, aberrant RhoA signaling may play a role [1]. In Alzheimer's disease, the RhoA/ROCK signaling pathway can promote its occurrence, as ROCK activation increases β-secretase activity, promotes amyloid-beta (Aβ) production, and Aβ further activates ROCK [3]. In hematological cancers, deregulated RHOA activity is linked to growth, progression, and metastasis, and recent sequencing studies have found both gain and loss-of-function mutations in primary leukemia/lymphoma [2]. In capillary malformation-arteriovenous malformation (CM-AVM) syndrome, loss of RASA1 may lead to constitutive activation of RhoA signaling in endothelial cells, increasing vascular permeability [4]. In myoblast fusion, RhoA in satellite cells is indispensable for correct muscle regeneration and hypertrophy, as its absence prevents proper cell fusion [5]. Also, in DNA damage response (DDR), RhoA has a role in mediating cell cycle arrest, with components like ATM, FEN1, ROS, and Rho-specific guanine exchange factors (GEFs) regulating its activation [6].

In conclusion, RhoA is a key regulator in multiple biological processes and is involved in various disease conditions. The study of RhoA through model-based research, such as KO/CKO mouse models (not specifically mentioned in the references but generally relevant in functional gene studies), helps in understanding its role in normal and disease-related biological functions, providing potential therapeutic targets for neurodegenerative diseases, cancers, and other disorders.