SOCS2 cis · 255 nt · 2025

HAR26

2xHAR.178

What it is

HAR26 (2xHAR.178) sits near SOCS2. In 2025 neuron experiments, a human-linked variant went with more SOCS2 and greater neurite outgrowth. That is a growth-of-connections phenotype, not a new neurotransmitter.

Why it matters

Causal HAR→SOCS2 / neuritogenesis.

Operator load

• 01 · ΔE

  Enhancer activity

  These stretches of DNA do not code for proteins. They act as volume knobs — turning nearby brain-development genes up or down at the right moment.

• 02 · C

  Compensatory substitution

  When one letter in the sequence changes, another often changes to keep the whole switch working. Evolution rewired the circuit without breaking it.

Cui et al. Nature 2025