Immunotherapies such as immune checkpoint blockade and adoptive cell transfer have revolutionized cancer treatment, but further progress is hindered by our limited understanding of tumor resistance mechanisms. Emerging technologies now enable the study of tumors at the single-cell level, providing unprecedented high-resolution insights into the genetic makeup of the tumor microenvironment and immune system that bulk genomics cannot fully capture. Here, we highlight the recent key findings of the use of single-cell RNA sequencing to deconvolute heterogeneous tumors and immune populations during immunotherapy. Single-cell RNA sequencing has identified new crucial factors and cellular subpopulations that either promote tumor progression or leave tumors vulnerable to immunotherapy. We anticipate that the strategic use of single-cell analytics will promote the development of the next generation of successful, rationally designed immunotherapeutics.

Removal of a vestibular schwannoma may result in ipsilateral hearing loss and facial palsy. So intraoperative neurophysiological monitoring is an important method for detecting and potentially preventing hearing loss and facial paralysis. Contralateral hearing loss after vestibular schwannoma removal is rare complications. The detection of acute contralateral hearing loss has not been reported intraoperatively and the pathomechanism is unclear. Our case was a 52-year-old female with left vestibular schwannoma removal surgery, who showed contralateral wave loss except for wave I in intraoperative brainstem auditory evoked potentials (BAEP) monitoring. Postoperative pure tone audiometry showed acute hearing loss in right ear, compatible with the intraoperative findings. Considering preserved wave I and no ischemic infarction on MRI, cochlear nerve problems during the operation might be considered. This case shows intraoperative monitoring of BAEP should be performed on the contra-lesion side as well, which could be helpful in inferring etiology of contralateral hearing loss.

Hemifacial spasm (HFS) is an involuntary contraction of muscles on one side of the face. It is caused by compression of the facial nerve by blood vessels. Microvascular decompression (MVD) is an effective treatment for HFS. However, complications such as hearing loss and dizziness may occur due to nerve deficits during surgery. To prevent this, neural monitoring is performed with brainstem auditory evoked potentials (BAEPs). In most hospitals, the presence or absence of BAEPs V waveform is used as an indicator for monitoring. Also, it tends to be intensively implemented only during the main procedure. In this report, we compare three cases in which there were differences in postoperative hearing complications depending on the presence of wave I. This suggests the importance of attention on wave I of BAEPs monitoring during MVD surgery and the need for acquiring wave I data until closing time as well during the main procedure.