- 
        Signature
      
 
      - 
        /s/ J.P. Galda, as attorney-in-fact for James Rolke
      
 
    
    
      
- 
        Stock symbol
      
 
      - 
        REVB
      
 
    
    
      
- 
        Transactions as of
      
 
      - 
        Jan 10, 2022
      
 
    
    
      
- 
        Transactions value $
      
 
      - 
        $0
      
 
    
    
      
- 
        Form type
      
 
      - 
        3
      
 
    
    
      
- 
        Date filed
      
 
      - 
        1/20/2022, 05:03 PM
      
 
    
    
    
   
     
   
 
  
    Transactions Table
  
  
    
      
        
          | Type | 
          Sym | 
          Class | 
          Transaction | 
          Value $ | 
          Shares | 
          Change % | 
          * Price $ | 
          Shares After | 
          Date | 
          Ownership | 
          Footnotes | 
        
      
      
          
            | holding | 
            REVB | 
            Common Stock | 
             | 
             | 
             | 
             | 
             | 
            681K | 
            Jan 10, 2022 | 
            Direct | 
             | 
          
          
            | holding | 
            REVB | 
            Common Stock | 
             | 
             | 
             | 
             | 
             | 
            2.14K | 
            Jan 10, 2022 | 
            By Spouse | 
            F1 | 
          
      
    
   
  
    Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)
  
  
    
      
        
          | Type | 
          Sym | 
          Class | 
          Transaction | 
          Value $ | 
          Shares | 
          Change % | 
          * Price $ | 
          Shares After | 
          Date | 
          Underlying Class | 
          Amount | 
          Exercise Price | 
          Ownership | 
          Footnotes | 
        
      
      
          
            | holding | 
            REVB | 
            Restricted Stock Unit | 
             | 
             | 
             | 
             | 
             | 
             | 
            Jan 10, 2022 | 
            Common Stock | 
            8.57K | 
             | 
            Direct | 
            F2, F3, F4 | 
          
          
            | holding | 
            REVB | 
            Restricted Stock Unit | 
             | 
             | 
             | 
             | 
             | 
             | 
            Jan 10, 2022 | 
            Common Stock | 
            65.1K | 
             | 
            Direct | 
            F3, F4, F5 | 
          
      
    
   
  
    * An asterisk sign (*) next to the price indicates that the price is likely invalid.
  
  
    Explanation of Responses:
  
  
  
    Remarks:
  
  Exhibit 24 - Power of Attorney.