Table 4. Correlation of VOCs with replication time and molecular markers of breast-derived cell lines.

Class	Compound	CDT	ER status	PgR status	HER2 status
		>48 h vs ≤48 h	(−) vs (+)	(−) vs (+)	(−) vs (+)
Hydrocarbons	2,4-Dimethyl-1-heptene	2.9 × 10−4	0.78	0.30	0.89
	1,3-Di-tert-butylbenzene	0.29	0.88	0.049	0.25
	2-Xylene	0.14	6.2 × 10−4	2.5 × 10−5	0.08
	2,3-Dimethylhexane	8.4 × 10−5	0.98	0.15	0.41
Secondary alcohol	Cyclohexanol	0.001	0.42	0.51	0.78
Fatty alcohol	2-Ethylhexanol	1.9 × 10−6	9.1 × 10−5	0.046	0.16
Carboxylic acid	Isobutyric acid, allyl ester	0.04	0.12	0.59	0.86
Ketons	2-Dodecanone	0.009	0.003	0.005	0.01
	2-Nonanone	0.11	0.001	0.58	0.85
	4-Methyl-2-heptanone	0.023	6.4 × 10−4	0.18	0.48
Manova		5 × 10−4	3.5 × 10−5	7.4  × 10−4	0.03

Comparison of GC-MS results in all breast-derived cell lines grouped based on CDT, expression of ER, PgR and amplification of HER2. Arrows indicate the trend for each compound in each group. The p-values obtained by t-test analysis for each compound and by MANOVA analysis for all compounds reported in Table 2 are shown. A p-value < 0.05 has been considered statistically significant.