Fascinating as these findings were?

Fascinating as these findings were = although these findings were fascinating, but...?

Context:

In the lamprey, two different lymphocyte lineages bearing clonally diverse lymphocyte receptors, VLRB and VLRA, were traced as analogs of mammalian humoral B cells and T cells respectively, that mediate B and T cell based antigen-specific adaptive immunity.

Fascinating as these findings were, the sea lamprey offered no evolutionary insights into the mysteries of self-recognition. An issue in later discussions was the distinction between autoimmune diseases caused by adaptive responses due to recombinatorial receptors of T and B cells, and autoinfiammatory diseases due to dysfunctional cells of the mammalian innate immune system.