This volume covers recent developments on the role, composition, and functional significance of intercellular and interorganellar transfer. It highlights the involvement of intercellular and interorganellar transfer in cell and developmental biology, differentiation, pathogen dissemination, shaping the genetic makeup of organisms, and the development of various diseases. Animals and plants evolved different communication mechanisms and transfer of molecules and organelles between cells and between organelles within the individual cells. Tunneling nanotubes (TNTs) in animals, discovered as recently as 2004, and their functional equivalent in plants, plasmodesmata, discovered over 100 years ago, are the membranous bridges that mediate the transfer of organelles, membrane patches, vesicles, DNA/RNA, and different molecules between cells. In addition, there are other means of transfer and communication between the cells, such as cytonemes, airinames, extracellular vesicles (exosomes), and others. Variations in cytoskeletal composition, morphology, modality, and connected cells suggest that these structures play a role in development, establishment of cell fate, progenitor cell differentiation, cell reprogramming, ferroptosis, generation of cancer stem cells, and various diseases. The exchange of intact membrane patches (trogocytosis) between cells of the immune system may modify the immune response. Additionally, the transfer of genetic information between nucleus and organelles and cells of different species can shape the species and evolutionary outcome. Viral and bacterial pathogens can hijack the inter-cellular transfer routes to spread more efficiently. Cell-to-cell transfer of animal and plant pathogens can also occur by the virological synapse (VS). These specialized pathogen-induced structures share similarities and differences with neurological and immunological synapses.