This is indeed a very encouraging and promising advance for cancer survivors who wish to achieve biological parenthood. We need to improve the quality of life for cancer survivors and will like to draw attention to the work done and reported from India, almost a decade ago. Bhartiya’s group from ICMR-National Institute for Research in Reproductive and Child Health, Mumbai reported pluripotent very small embryonic-like stem cells (VSELs) along with the spermatogonial stem cells (SSCs) in the mouse [PMID: 32578128] and human [PMID: 20805580] testis. Being quiescent, VSELs survive chemotherapy in mouse testis [PMID: 25903688, PMID: 27189070] and also total body irradiation in mouse bone marrow. Kurkure’s group from Tata Memorial Hospital, Mumbai showed that quiescent VSELs were detected even after more than a decade in azoospermic human testicular biopsies of young survivors of childhood cancer [PMID: 26553338]. We have also reported successful culture of chemoablated mouse testicular tissue and that VSELs (that survived busulphan treatment) differentiated into sperm [PMID: 25903688]. Interestingly, on transplanting mesenchymal stromal cells (MSCs) in chemoablated mouse testis, spermatogenesis was completely restored and sperm mobilized into the cauda region [PMID: 27663915]. This approach of using MSCs to restore spermatogenesis from VSELs is non-invasive and safe based on published literature. Even allogenic MSCs will be effective to restore spermatogenesis. Similar data exists for the mouse ovaries too [PMID: 25779995]. Readers may also refer to additional publications [PMID: 26576728, PMID: 40124247, PMID: 41779358].

Deepa Bhartiya, PhD TZAR Genomics India Pvt Ltd, Lower Parel, Mumbai 400013, India deepa.bhartiya@tzarlabs.com https://orcid.org/0000-0002-5384-3998

Purna Kurkure, MD Paediatric Haemato and Oncologist, SRCC Children’s Hospital, Mumbai purnakurkure.dr@narayanahealth.org