The cochlea of the inner ear contains a basilar membrane carrying rows of hair cells which respond to a gradient of sound frequencies.

The SLO gene encodes a calcium-regulated potassium channel. that affects frequency sensitivity of hair cells.

Normal splicing results in low calcium-sensitivity of the potassium channel and are found in high-frequency hair cells.

Alternative splicing that incorporates the STREX exon results in high calcium-sensitivity and are found in low-frequency hair cells.