TOP1（topoisomerase (DNA) I），癌症关联基因，基因ID：7150，这个基因编码一种DNA拓扑异构酶，这种酶在转录过程中控制和改变DNA的拓扑状态。这种酶催化单链DNA的瞬间断裂和重新结合，使单链DNA彼此穿过，从而改变DNA的拓扑结构。该基因定位于20号染色体，并具有位于1号和22号染色体上的假基因。This gene encodes a DNA topoisomerase， an enzyme that controls and alters the topologic states of DNA during transcription. This enzyme catalyzes the transient breaking and rejoining of a single strand of DNA which allows the strands to pass through one another， thus altering the topology of DNA. This gene is localized to chromosome 20 and has pseudogenes which reside on chromosomes 1 and 22.关联癌症：结直肠癌，卵巢癌。