The Wnt signaling pathway, an evolutionarily conserved signal transduction pathway, is widely present in invertebrates and vertebrates. The Wnt signaling pathway plays a crucial role in early embryonic development, organogenesis, tissue repair, and many other physiological processes. The mutation of key proteins involved in this pathway can lead to abnormal activation of signals, and potentially induces the occurrence of cancer. In 1982, R. Nusse and H.E. Varmus identified the first Wnt gene from a mouse mammary tumor and named it Int1 (integration 1). Continued research found that the mouse Int and Drosophila Wingless (Wg) genes are homeotic, and thus combined their names to Wnt. H.E. Varmus himself also won the 1989 Nobel Prize in Physiology or Medicine for his great contribution in oncology.

Cluster of differentiation, or CD molecules, are cell surface markers that are used for identification of cell types in pathology and other bioscience disciplines. The expression levels of CD markers may increase or decrease (or disappear altogether, at least to undetectable levels) when cells (for example, leukocytes, red blood cells, platelets, and vascular endothelial cells, etc.) differentiate into new and different lineages. Depending on the CD marker, the expression level may identify a phenotype for different segments of cells, such as when they become active or diseased. Most CD molecules are transmembrane proteins or glycoproteins, including extracellular regions that bind a ligand or opposing receptor, transmembrane regions to anchor the CD marker into the cell, and cytoplasmic regions that may confer some adaptor or catalytic function. Some CD molecules can also be "anchored" on the cell membrane by means of inositol phospholipids. A few CD molecules are carbohydrate haptens. The study of CD molecules can be used in many basic immunology research fields, such as the relationship between CD antigen structure and function, cell activation pathway, signal transduction and cell differentiation, etc. It can be used clinically for disease mechanism research, clinical diagnosis, disease prognosis, efficacy tracking and treatment, and more. CD molecules such as CD4, CD8, CD25, etc. can be used to identify populations of cells when studying samples by flow cytometry or immunofluorescence.

The Hippo signal is very conservative in evolution. It regulates organ size and tissue stability by regulating cell proliferation, apoptosis, and stem cell renewal. The core process of Hippo signaling is a kinase tandem process, Mst1/2 and Sav1 form a complex, phosphorylate and activate Lats1/2; Lats1/2 kinase then phosphorylates and inhibits transcriptional coactivators Yap and Taz. Yap and Taz are the most important effectors downstream of the Hippo pathway. Upon dephosphorylation, Yap and Taz translocate to the nucleus and interact with TEAD1-4 or other transcription factors (such as CTGF) to induce gene expression, thereby initiating cell proliferation and inhibiting apoptosis.

The extracellular signal-regulated kinases, or ERK1/2 (MAPK1/MAPK3, p44/42MAPK), are signaling molecules belonging to the mitogen-activated protein kinase family (MAPKs) that are commonly located in the cytoplasm of eukaryotic cells. In concert with various other molecules in the signaling cascade acting under different surface or intracellular receptors, ERK1/2 act as catalysts in the phosphorylation of serine/threonine and are negatively regulated by the bispecific (Thr/Tyr) MAPK phosphatase family (called DUSP or MKP) and specific inhibitors to MEK activity (such as U0126 and PD98059).