HIF1A and neoplasm: Except of these circRNAs mentioned above, a number of other circRNAs has been identified to modulate the expression of HIFs, especial for HIF-1α, in favor of the progression and glycolysis of tumor cells under normoxia or hypoxia, which include circNRIP1 [40], circHIPK3 [41], CircZFR [42], circ_03955 [43], hsa-circ-0000211 [44], circPIP5K1A/hsa_circ_0014130 [45], and so on (Table 2, Fig. 3).