How can two contradicted gene sets be enriched in a cancer sample in GSEA analysis?

Question

[Amr]

How can two contradicted gene sets be enriched in a cancer sample in GSEA analysis? For example in GSEA analysis of cancer sample vs normal sample, How can HALLMARK_UV_RESPONSE_UP and HALLMARK_UV_RESPONSE_DN be enriched in a cancer sample at the same time? What does it mean?