Book excerpt: Tyrosine kinases, which catalyze the transfer of a phosphate from ATP to a hydroxyl group of a tyrosine residue, play a plethora of roles in the regulation of diverse functions in normal cells including cell growth, motility, differentiation, and metabolism. Moreover, they are also associated with oncogenesis. Tyrosine kinases are mainly classified as receptor tyrosine kinases and non-receptor tyrosine kinases, including crucial members. Epidermal growth factor receptor (EGFR) belongs to the ERBB family of receptor tyrosine kinases along with three other closely related receptors, namely HER-2, HER-3 and HER-4. EGFR and HER-2, lead to autophosphorylation of the intracellular domain through tyrosine kinase activity and subsequent stimulation of downstream cascade that may result in proliferation, suppression of apoptosis, metastasis and angiogenesis. On the other hand, c-Abl (Abl-1) is a non-receptor tyrosine kinase, which is also essential in the regulation of several antiapoptotic and proliferative signal transduction pathways. They have mainly been identified as important targets for several types of cancer such as EGFR for non-small-cell lung cancer, glioma and colorectal cancer, HER-2 for breast and colorectal cancers and Abl for chronic myeloid leukemia. One of the major platforms that they have participated in is neurodegenerative disorders such as Parkinson’s disease, Alzheimer’s disease and amyotrophic lateral sclerosis. Aberrant activity of tyrosine kinases, in particular EGFR and Abl, have been reported to induce apoptosis and cell cycle arrest in response to a wide range of stimuli resulting in neurodegeneration and neuroinflammation. The main goal of this Research Topic is to identify new and potent effective tyrosine kinase inhibitors to be effective in cancer and neurodegenerative disorders.