NPAS2 and ovarian carcinoma: We further evaluated the correlations between PER1 and these 10 interacting proteins based on the GEPIA database and found that the expression of PER1 in ovarian cancer was correlated with that of ARNTL, CLOCK, CRY1, CRY2, CSNK1D, CSNK1E, NPAS2, and PER3 (Figure 4C).