Among cell surface markers, CD44 is considered the main marker for identifying and isolating the cancer stem cells (CSCs) among other cells and has attracted significant attention in a variety of research areas. Many studies have shown the essential roles of CD44 in initiation, metastasis, and tumorigenesis in different types of cancer; however, the validity of CD44 as a therapeutic or diagnostic target has not been fully confirmed in some other studies. Whereas the association of specific single nucleotide polymorphisms (SNPs) in the CD44 gene and related variants with cancer risk have been observed in clinical investigations, the significance of these findings remains controversial. Here, we aimed to provide an up-to-date overview of recent studies on the association of CD44 polymorphisms and its variants with different kinds of cancer to determine whether or not it can be used as an appropriate candidate for cancer tracking.

中文翻译：

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CD44 多态性及其变体，作为癌症研究中不一致的标记。

在细胞表面标志物中，CD44 被认为是在其他细胞中识别和分离癌症干细胞 (CSC) 的主要标志物，并在各种研究领域引起了极大的关注。许多研究表明 CD44 在不同类型癌症的起始、转移和肿瘤发生中发挥重要作用；然而，CD44 作为治疗或诊断靶点的有效性尚未在其他一些研究中得到充分证实。尽管在临床研究中已经观察到 CD44 基因中的特定单核苷酸多态性 (SNP) 和相关变异与癌症风险的关联，但这些发现的意义仍然存在争议。这里，