Table 2. Characteristics of valid two-class OPLS-DA models based on quantitative hormone concentrations from 13 hormones following H295R cell exposures with either 1000 ng/mL MC-LR, M. aeruginosa PCC7806 or PCC7806mcyB− extracts, compared to the positive control (1.5 μM forskolin).

Classes	R2(x) (cum)	R2(y) (cum)	Q2(x) (cum)	CV-ANOVA P-value	Steroids predictive for class difference incl. pVIPa
PC vs. MC-LR 1000 ng/mL	0.93	0.58	0.52	0.039	11-deoxycorticosterone (1.9), 17-hydroxypregnenolone (1.5), androstenedione (0.96), DHEA (0.67), 17-hydroxyprogesterone (0.64)
PC vs. PCC7806 (high)	0.97	0.89	0.83	1.1×10−3	11-deoxycorticosterone (3.1), 17-hydroxypregnenolone (1.0), DHEA (0.89)
PC vs. PCC7806mcyB− (high)	0.91	0.84	0.81	1.3×10−4	11-deoxycorticosterone (1.9), 17-hydroxypregnenolone (1.6), androstenedione (1.5), DHEA (1.2), pregnenolone (0.52)

^a Selection criteria: predictive Variable Importance for the Projection (pVIP) > 0.5; p[1] >|0.05|; p(corr)[1] >|0.5|.