Through detecting whole-blood expression of native α7 nicotinic subunit and the duplicated isoform of the human α7 neuronal nicotinic acetylcholine receptor gene (CHRFAM7A), A Courties et al. found that the expression of CHRFAM7A in critical COVID-19 patients was lower than the control (1.35  ±  2.5 versus 3.45  ±  4.2, p =  0.06) and COVID-19 patients not expressing CHRFAM7A subunit showed higher level of C-reactive protein (p =  0.04) and more pronounced lymphopenia (p = 0.05 for total lymphocyte, p =  0.03 for % live lymphocytes) [143]. Here, CHRFAM7A is linked to lymphopenia.