RB1 and obesity due to melanocortin 4 receptor deficiency: Since it has been shown that Rb, under certain circumstances, replaces K in the organism, which is essential for the proper functioning of the sodium-K pump (RELMAN 1956), (Krulik et al. 1977) and obesity is characterized by K deficiency in the body (Szczerbowska-Boruchowska et al. 2023a), the changes in Rb levels in tissues of obese individuals may reflect impaired Na+/K+-ATPase activity, leading, among other things, to the formation of reactive oxygen species (ROS) in the organism (Amin et al. 2020).