TFRC and Hypokalemia: The interrelation between hypokalemia and endocytosis was reported decades ago when early studies revealed that potassium depletion blocks CME and leads to the aggregation of clathrin in the cytoplasm, thus removing it from functioning in vesicle-coating [73] Some reports demonstrated that hypokalemia inhibited the endocytosis of the transferrin–transferrin receptor (Tf/TfR) complex and protected cells against poliovirus, but not rhinovirus type 2.