**3. Application of tumor organoids**

The lack of a physiologically relevant model system has delayed the therapeutic development process, and many candidates have failed in clinical trials [4]. Cancer *Organoids and Commercialization DOI: http://dx.doi.org/10.5772/intechopen.104706*

organoids are near-physiological replicas of their parent tumors and bridge the gap between drug screening and clinical trials. Organoids have been utilized to examine personalized cancer patient responses in several research [32, 44, 45]. It may also be utilized to look at the epigenetic and genetic changes that cause drug resistance [46]. Tumor organoids can accurately predict chemotherapeutic response and resistance for certain drugs in some cancers [47, 48]. Finding the right therapeutic combination can be a challenge, and tumor organoids can help solve this dilemma and can make personalized medicine a reality [49]. The advances in genetic engineering technologies like CRISPR-Cas9 are implemented on organoids further to confirm medication sensitivity to specific mutations [50]. Organoids may also be used for pharmacokinetic research, critical in drug development. Results suggest that drug-transporters, their efflux transport functions, drug-metabolism can be efficiently studied using organoids [51]. In addition to cancer biobanks, organoids have a significant role to play in immunotherapy, a kind of cancer treatment in which the patient's immune system is used to eliminate tumor cells [52]. Organoid-based models are explored to study the effect of tumor-immune cell interaction using a coculture system with both components [53].
