 Anti-cancer drug resistance is a complex process that arises from altering in the drug targets and advances in DNA microarray, proteomics technology, and targeted therapies provide new strategies to overcome drug resistance. Although the design of new chemotherapy agents is growing quickly, effective chemotherapy agents have not been discovered against advanced stage cancer such as invasion and metastasis. The cancer cell resistance against anti-cancer agents can be due to various factors including genetic differences, multi-drug resistance, cell death inhibiting, apoptosis suppression, altering in drug metabolism, epigenetic changes, and drug targets, enhancing DNA repair and gene amplification. Treatment failures by common chemotherapy agents are discussed in different types of cancers. This article was authored by Beyzad Mansuri, Ali Mohamedi, Siddharth Davudian, and others. We are article.tv. Links in the description below.