A system for identifying receptor-ligand pairs active in intercellular communications relating to cell replication by transforming single cell RNA-seq. data into a visualized display, wherein the system is for cellular sub-population detection and identification of receptor-ligands that orchestrate intercellular communication between the sub-populations, the system comprising: a sequencer for providing RNA-seq data from a plurality of individual cells of a cancer or tumor; an interface in communication with the sequencer for receiving the RNA-seq data from the sequencer, said interface configured to perform the steps of; obtaining and storing a plurality of normalized single-cell data sets generated by the sequencer; obtaining a plurality of data sets from a curated gene list of receptor-ligand pairs; normalizing the data from the curated gene list; inputting reference genome sequences from library and auxiliary bio data bases; selecting genes into a gene set by extracting their normalized transcript abundance data, assigning states to each receptor-ligand pair in each cell, removing genes that exhibit low variation in transcript abundance from the set, applying unsupervised clustering to identify sub-clusters and providing sub-cluster data; wherein the sub-clusters comprise cellular sub-populations identified based on pair-wise differences between individual cells and similarity of cellular transcriptomes; and cross-referencing the selected gene data with the reference genome sequences data and the normalized curated list of receptor-ligand pairs, thereby identifying expressed ligands and receptors across the cellular sub-populations, and storing the results in a results storage database; an output device, in communication with the storage database through an interface, wherein said output device is configured to obtain the identified sub-cluster and receptor-ligand data from the storage device, and to provide a display in the form of a heatmap or ReLiCoMap from which a clinician can identify receptor-ligand pairs that orchestrate intercellular communication between the identified sub-populations within the cancer or tumor. a sequencer for providing RNA-seq data from a plurality of individual cells of a cancer or tumor; an interface in communication with the sequencer for receiving the RNA-seq data from the sequencer, said interface configured to perform the steps of; obtaining and storing a plurality of normalized single-cell data sets generated by the sequencer; obtaining a plurality of data sets from a curated gene list of receptor-ligand pairs; normalizing the data from the curated gene list; inputting reference genome sequences from library and auxiliary bio data bases; selecting genes into a gene set by extracting their normalized transcript abundance data, assigning states to each receptor-ligand pair in each cell, removing genes that exhibit low variation in transcript abundance from the set, applying unsupervised clustering to identify sub-clusters and providing sub-cluster data; wherein the sub-clusters comprise cellular sub-populations identified based on pair-wise differences between individual cells and similarity of cellular transcriptomes; and cross-referencing the selected gene data with the reference genome sequences data and the normalized curated list of receptor-ligand pairs, thereby identifying expressed ligands and receptors across the cellular sub-populations, and storing the results in a results storage database; obtaining and storing a plurality of normalized single-cell data sets generated by the sequencer; obtaining a plurality of data sets from a curated gene list of receptor-ligand pairs; normalizing the data from the curated gene list; inputting reference genome sequences from library and auxiliary bio data bases; selecting genes into a gene set by extracting their normalized transcript abundance data, assigning states to each receptor-ligand pair in each cell, removing genes that exhibit low variation in transcript abundance from the set, applying unsupervised clustering to identify sub-clusters and providing sub-cluster data; wherein the sub-clusters comprise cellular sub-populations identified based on pair-wise differences between individual cells and similarity of cellular transcriptomes; and cross-referencing the selected gene data with the reference genome sequences data and the normalized curated list of receptor-ligand pairs, thereby identifying expressed ligands and receptors across the cellular sub-populations, and storing the results in a results storage database; an output device, in communication with the storage database through an interface, wherein said output device is configured to obtain the identified sub-cluster and receptor-ligand data from the storage device, and to provide a display in the form of a heatmap or ReLiCoMap from which a clinician can identify receptor-ligand pairs that orchestrate intercellular communication between the identified sub-populations within the cancer or tumor.