More specifically, TIMP-2 was determined to decrease the SP in A549 lung cancer cells through decreased transcription of ABCB1 (ATP-binding cassette sub-family G member 1), ABCG2 (ATP-binding cassette sub-family G member 2), and AKR1C1 (Aldo-keto reductase family 1 member C1) [39]. Here, AKR1C1 is linked to lung cancer.