ID	group	group2
YC_2_1	YC	young_control
YC_2_3	YC	young_control
YE_2_1	YE	young_enriched
YE_2_3	YE	young_enriched
OC_2_1	OC	old_control
OC_2_5	OC	old_control
OE_2_1	OE	old_enriched
OE_2_3	OE	old_enriched