Based on the provided references, unfortunately, there is limited information to comprehensively describe the gene Gan. Gan might be a gene of significance in the context of cancer-related research considering the various cancer-associated studies citing it [1-10]. However, without abstracts containing details about its function, associated pathways, or the use of gene knockout (KO) or conditional knockout (CKO) mouse models, a detailed analysis of its biological function is not feasible.

No findings from KO/CKO mouse models or loss-of-function experiments could be gleaned from the given references. The references seem to cover a range of cancer-related topics such as studies on amitosis in Yoshida sarcoma [1], purification of toxohormone [2], and classification of meningiomas [3], but none provide direct insights into the gene Gan's function.

In conclusion, due to the lack of relevant information in the provided references, the essential biological functions of Gan remain unclear. There is no evidence from the references to highlight the contribution of Gan KO/CKO mouse models to specific disease areas. Further research, especially in-depth functional studies using genetic models like KO or CKO mouse models, would be needed to understand the role of Gan in biological processes and disease conditions.