Epithelial cells form a barrier to separate the body from either the outside world or the milieu of organs. Intercellular communication is essential to enable various biological and immunological processes to ensure protection of the barrier function, and for the establishment of a healthy cellular environment. My research interest is driven by my paradigm-shifting discovery that, in contrast to the prevailing view, the so-called basal cells, present in pseudostratified epithelia and have never in contact with the luminal side of an organ, in fact extend “antenna-like” body projections that cross the tight-junction barrier to reach the lumen. This previously unrecognized property of basal cells is observed in several tissues located in the male reproductive, gastrointestinal and upper respiratory tracts, indicating that it is a widespread phenomenon. This prompts the necessity of re-interpretation of our understanding of epithelial biology, apical sensing, and signal transduction in health and disease. Using epididymis as a model, my research work also shows that basal cells transmit their luminal finding to adjacent cells and control various functions including proton secretion from the V-ATPase expressing clear cells via cell-cell interactions with paracrine factors. My research therefore focuses on two broad aims: 1) to understand the intercellular communication network in the epithelial function, in particular the cell-to-cell interactions between basal cells and the neighboring cells in pseudo stratified epithelia; and 2) to understand the role of epididymis in sperm maturation and male fertility. My research would have broad implications for understanding of epithelial function in general in addition giving insight into intercellular communication network in the epididymis, and would have equal potential to provide insights into the causes of some unexplained male infertility cases, yet may also provide insight for the development of novel male contraceptive.