This cluster of papers focuses on fertility preservation in cancer patients, with an emphasis on techniques such as ovarian tissue cryopreservation, oocyte maturation, and embryo development. It explores the impact of gonadotoxic therapy on ovarian function, reproductive aging, and the quality of cryopreserved oocytes. The cluster also delves into the molecular and cellular aspects of follicle development and the role of various growth factors in preserving fertility.